I'm 5'7'' and I don't complain about not being tall.
Ok, it is settled then. So shut up about it now, bitches.
What routes are easier if you are short
Shorter climbers will, generally speaking, have an easier time climbing than taller people. If two climbers are the same shape (ie shorter not stockier than the taller climber) then the shorter climber is at a distinct advantage, and here is why.
As a climber gets taller the climber's mass goes up as a length raised the the third power (b/c mass is proportion to volume).
The limiting factor for climbing certainly must be related to finger strength. The force a muscle can generate is roughly proportion to the cross-sectional area taken perpendicular the fibers of the muscle. Thus strength goes up as the length, but raised to the second power.
So smaller individuals will have a greater cross-sectional area (strength) compared to their volume (mass). Strenght to mass ratio.
If you want an non-human example - go to your local zoo and watch the gibbons (small) and the gorillas (very large). The gibbons are much better climbers - and their small size is one of the contributing factors, and probably the dominant factor.
Now in rock climbing things are a bit more complicated b/c
1. Not all humans are the same shape, although its not clear that shorter people are stockier.
2. Rock is not necessarily uniform in the distribution of holds. Thus there will be some climbs where the holds are space to make it significantly more difficult for shorter (or taller) climbers.
As a climber gets taller the climber's mass goes up as a length raised the the third power (b/c mass is proportion to volume).
The limiting factor for climbing certainly must be related to finger strength. The force a muscle can generate is roughly proportion to the cross-sectional area taken perpendicular the fibers of the muscle. Thus strength goes up as the length, but raised to the second power.
So smaller individuals will have a greater cross-sectional area (strength) compared to their volume (mass). Strenght to mass ratio.
If you want an non-human example - go to your local zoo and watch the gibbons (small) and the gorillas (very large). The gibbons are much better climbers - and their small size is one of the contributing factors, and probably the dominant factor.
Now in rock climbing things are a bit more complicated b/c
1. Not all humans are the same shape, although its not clear that shorter people are stockier.
2. Rock is not necessarily uniform in the distribution of holds. Thus there will be some climbs where the holds are space to make it significantly more difficult for shorter (or taller) climbers.
5'7 isn't short--it's tall compared to me. Although I do agree with most of your whiney theories--I use them myself. Try being 5'3 and see how whiney you get on reachy moves. A short person has to hike feet and lock off much lower and be more dynamic to do a move that a tall person doesn't even notice because they just stick their long-ass arm up in the air and grab the next jug hold (skipping all of the "intermediates") that a tall person could never hold onto because they are weak and don't even know what reachy moves entail. Plus, tall people only have to do half as many moves as a short person (they call it endurance, but it's really just climbing half as much). 
Hauling a big ego up a route adds at least a full grade.
What makes one rock climb harder than another rock climb?
Two things:
1.) The holds get worse.
2.) The holds get farther apart.
It is distinctly reason number 2 that being taller is more often an advantage. However, there is some middle ground. While being shorter than whatever height is a blatant disadvantage, perhaps being 6'0" tall or greater is a distinct disadvantage as well. With longer arms each muscle has to pull a presumably larger load over a greater distance, among other leverage issues. Seems that being average size, for a male, - 5'9" or 5'10" is best in most circumstances, however, I would say that being super wicked tall (a la Andrew) is more often an advantage than a disadvantage, and being short (a la Ms. Boland) is more often a disadvantage. One rarely hears a climber say, "Man, I wish that hold weren't so close." And how often do you hear of tall people lurping between holds that shorter folk must pull 2 or 3 moves to get between?
I think it is a pretty clear fact that women would, on the very highest level, climb more frequently at the same limit as their male counterparts if they were a few inches taller. Josune Bereziartu is 5'7" or 5'9" or something, and she's climbed 9a or 9a+. This, too, speaks to the fact that being shorter than, say 5'6", is a greater disadvantage than being mutantly tall.
That all having been said, I would say the Red works out better for short folks better than most climbing areas I've experienced. So how about everybody keeps bitching because it's more fun that way.
Two things:
1.) The holds get worse.
2.) The holds get farther apart.
It is distinctly reason number 2 that being taller is more often an advantage. However, there is some middle ground. While being shorter than whatever height is a blatant disadvantage, perhaps being 6'0" tall or greater is a distinct disadvantage as well. With longer arms each muscle has to pull a presumably larger load over a greater distance, among other leverage issues. Seems that being average size, for a male, - 5'9" or 5'10" is best in most circumstances, however, I would say that being super wicked tall (a la Andrew) is more often an advantage than a disadvantage, and being short (a la Ms. Boland) is more often a disadvantage. One rarely hears a climber say, "Man, I wish that hold weren't so close." And how often do you hear of tall people lurping between holds that shorter folk must pull 2 or 3 moves to get between?
I think it is a pretty clear fact that women would, on the very highest level, climb more frequently at the same limit as their male counterparts if they were a few inches taller. Josune Bereziartu is 5'7" or 5'9" or something, and she's climbed 9a or 9a+. This, too, speaks to the fact that being shorter than, say 5'6", is a greater disadvantage than being mutantly tall.
That all having been said, I would say the Red works out better for short folks better than most climbing areas I've experienced. So how about everybody keeps bitching because it's more fun that way.
I don't know much, but I know that.
It is hard to make an arguement that hold getting further apart is the primary source of difficulty of a climb (ie why taller climbers are at an advantage). The other source (holds getting worse) is also important, and is probably the primary limiting factor in many cases. If you cannot hold the hold you are on, (ie it is too small) then it does not matter how far it is to the next one, and being taller is irrelevant.
Smaller holds (worse) will feel relatively bigger to people with small hands, or small people.
Note leverage for muscles in not really an issue. Leverage, or mechanical advantage, is the ratio of the muscle lever arm compared to the load lever arm. This does not vary generally with size within a species.
The optimal size for a rock climber will be dictated by the rock (distance between holds) but will always be the smallest size that will get you between holds.
Smaller holds (worse) will feel relatively bigger to people with small hands, or small people.
Note leverage for muscles in not really an issue. Leverage, or mechanical advantage, is the ratio of the muscle lever arm compared to the load lever arm. This does not vary generally with size within a species.
The optimal size for a rock climber will be dictated by the rock (distance between holds) but will always be the smallest size that will get you between holds.