There's nothing stopping you from browsing, and there are now tons of sites and databases and forums etc to help you find similar or related music, including one built into iTunes (ping I think? did my best to disable & hide it because "F-OFF and stop watching my usage preferences for your marketing").
The issue here boils down to one simple thing: Control. People want control of their (very expensive) mobile - or any - device, and Apple wants control of how you use it and what you have access to when you use it. That's obvious with just about every aspect of iOS (yes I have an iPhone). Apps, settings, etc it's all their way or no way. I can't uninstall the Stocks app. Why? You can't tell me there's code in it needed by iOS, and if there was, why not move it to a required shared object / DLL type file and let.me.delete.Stocks. Now there are Facebook settings in the iOS general settings - WHY?! I deleted my facebook account and don't even have the app installed!
Control. I don't even hate U2, but this whole debacle pisses me off to no end. It may not have auto-downloaded, but I can't get it off my list unless I also remove all the other content that I (should not have!) bought on iTunes and CHOSE not to have on the iPhone this month. I went back to buying CD's and ripping them - you know why? Control. I can control the quality, whether I see them in the list, which cover artwork to embed, everything.
There's simply no intuitive, nice way of taking control away from a user without someone getting upset, and I don't see how anyone is surprised by that.