I used to think the same thing about waiting the whole time. That was until the last two Springsteen tours. The GA lines there were run exceptionally well by a few fans who kept a list of names and wrote numbers on each person's hand. That way, those who arrived first were actually first to get to enter, and there was a way to actually tell who was a cutter and who wasn't.
It also made things a whole lot nicer, in that we could "check in" early, enjoy whatever city we were in for a few hours, and come back and have our spot all set. Surprisingly, everyone, in every city, was agreeable to the whole situation. The venue staff all appreciated it (after taking the time to understand it) and it made for a great two tours. It's pretty much the "norm" now for Bruce shows, whether during a regular tour, or just for a specialty show.
Perhaps its success was attributable to higher percentage of "older" people in the Springsteen fanbase. I guess with U2's success at continuing to pull in younger fans, this tour is going to have to deal with the attitudes of people who are willing to sit all day in the rain and wind (or hot sun or whatever) to feel like they're bigger fans. I had that attitude at one time, so I understand it. But the fact of the matter is it only makes you a cold & wet (or sunburned & fatigued) fan, not a bigger one.
I hope some smart U2 fans will learn from the Springsteen GA example and get something organized for this tour. Copping an attitude about waiting in line all day would be a regression to a disorganized past with the ever present danger of chaos. It's one thing to talk tough on the internet, and another to actually confront a "cutter" whose willing to throw down. When everyone has agreed to a system, and has numbers marked on their hands, it's a lot easier to identify and deal with such a problem.