All the "other" coins that will still be mine able are shit coins. So if you dont mind dealing in shit coins / pump and dump frauds then yes GPU still have a future. If you dont want to lend your resources to these coins then get all the Eth that you can right now.
Yes all other coins are not worth the electricity spent.
Pay attention all of you trolls, once eth is done, mining profits will crash so hard, what is keeping other coins profitable right now is not the coin per se is eth and only eth.
Unless a g3 coin comes round and makes the whole thing profitable again, i see no future for gpu mining after eth goes pos.