Rippetoe, unlike what he is represented in this thread, is not the be all and end of training and you will find many slightly different variations of the squat.
The basics such as not rounding the lower back and keeping the shoulders and lats tight will always be the same though. Just practice both versions and see which you prefer.
Oh, I know that I will prefer the EFTS. Maybe because I'm taller.
Wait....there are exercises besides squat rack barbell curls?
Seriously though, there is no real excuse for this to ever happen. Me and my buddy would always ask and make sure there was nobody around or using the rack, and if anyone came by asking to use it/how many sets we have left, we would just go and put the bar on (one of the numerous) bench press pad. Works just as well.
Oh, and kids are always going to be obnoxious. It's just embedded in them at that age. They'll act too big for their britches. Just how it is. It sucks, and is bullshit, but that's that.
I am always courteous and nice to everyone at the gym, so I hope that karma, or whatever catches up and treats me well. Even if it doesn't, there's no reason why you can't be polite.
Wait a sec, you used the squat rack for curls? You can do curls pretty much anywhere.