I'm not sure who started this or not, but whoever did really needs to be slugged in the face. When I go to the gym on legs day, I want to be able to use the squat rack. I realize not everything revolves around me and I'm well aware of extending courtesy to fellow lifters when they are using the equipment, but come on... curling in the squat rack? If you want to do it when there are plenty of other, unused racks, go for it. Sure, it's still pointless, but at least people who come in to squat can actually squat. There are plenty of other places in the gym where you can curl your weight. Half the time you're doing it wrong anyway, but you'll continue to come in 5 days a week and work arms, neglecting everything else.
I have immense respect for those that are willing to give the "big 3" a shot and try to stick with them. I see far too few deciding not to deadlift or squat in the gym. Injury is one thing, but more times than not, it's simply exercises people don't want to do.
I want people to read this very clearly: YOU CAN'T GET BIG WORKING YOUR ARMS 5 DAYS A WEEK!
You can't. You just can't. You can if you want, but don't really expect to go anywhere. Over-training is counterproductive.