I really don't mind mining alt coins. Investing money into it is one thing, but it doesn't really hurt much to mine a few alt coins. Some of the alt coin projects that are interesting are the ones that aren't simply clones and try new mechanics like Proof of Stake. Yes, many alt coins are merely pump and dump, but some are acting as proof of concepts to try and innovate crypto coin technology and I think those types are worth investing your hash rate into to see how well or poorly the new concept plays out.