Although there are times when it sounds appealing, I don't think I'd care for spray-painted arrows pointing out all the holds.
Heck, if this is what someone is looking for, just go the the gym. Look for the next blob of plastic and you know where you need to reach/place your foot/etc.
Getting on a route that has no chalk on it and you have no other beta about it is part of the appeal. Finding a small crimp and deciding if this is the hold you work off of or do you spend time trying to find something better.
I guess this type of head-game isn't for everyone.