Indeed it is a good idea. I auto switch between Ethereum, and other equihash algorithms (Zcash, ZenCash, and Zclassic). Even mining bitcoin gold has been profitable lately. This year will see an explosion of alt coins, including Ethereum classic, so mining will still very much be a profitable thing in 2018, even after Ethereum goes to proof of stake. But mine it while you can and hang onto it!! Personally, though, I think the real one to pay attention to is EOS, which may someday overtake Ethereum (like the old tech startups in the 90s and 2000s) but I don't think it will just fade away into nothing.