I would say that some alt coins are an obvious waste of time.  But to say that all of them are a waste of time is not true.  You need to know when to trade your alt coins for a different alt coin or bitcoin.  Watch the site coinwarz.com to see what alt coins stay stable and what you should be mining for. http://www.coinwarz.com/cryptocurrency  I'm sure there are others out there too, but I have not searched for them.