Also, keep in mind people generally listen to music from their age - so I listen to U2, my dad listens to a lot of Rolling Stones and The Who, my grandpa listens to a lot of Sinatra. My grandpa doesn't really listen to U2 and my dad doesn't listen to Kanye. U2 is of my age. RHCP is of my age. I mean I also like Stones and Sinatra, but I am really too young to have any growing up experiences with them. But after you are done growing up, your tastes are pretty much set...so you don't venture out a ton for new music (the only area I do is jazz music...I am always listening to new artists).
Result: all those other bands on the lineup are way off my radar...I suppose I could just go for the U2 portion, but wouldn't I rather go to a show in NYC where I can get a hotel room and do some other things, and then just show up at the concert??