Couldn't agree less about the layout. It's a disorganized mish-mash on the desktop, and filled with utterly unnecessary fluff like comment boxes that float around the screen when you click on them, forcing you to move your mouse unnecessarily to get back to them and lengthening the time until you can start typing. Support for inlined animated GIFs is hardly something I'd consider a plus, just a way for people to annoy me. And I've never had a single spambot try to add me on Facebook, whereas on Google+ the majority of followers are in fact spambots.
As for why it didn't catch on, that's because Facebook already has achieved critical mass, and so Google+ can't compete with it. Why would you use a social network most of your friends aren't on? You wouldn't, and because you wouldn't, nor would they -- it's chicken and egg. The MySpace comparison doesn't hold water because most people had gotten bored of MySpace and stopped using it before Facebook came along, and even those who were still using it had relatively small, activity-free friend networks. (Speaking personally, I didn't know anybody who had more than 15-20 active friends on MySpace at the absolute most by the time Facebook arrived.)
It's unfortunate, but the chances of anybody beating Facebook without an amazing killer app that can't be easily copied (or a major, major faux pas on Facebook's part) are pretty much zero. Doubly so when their only reason for creating the network in the first place is to mine even more data on their users, which was Google's only reason for creating Google+.