Of course alt coins have future. Specially some of them ETH, Monero, Waves, LiteCoin and others already show good sustainability. Also, in the distant future BTC at some point will stabilize its price and it certain that people will turn to alt coins.
That is a belief out of ignorance. If you are conversant with the crypto market today, then you will realize that some altcoins have died, some are good as dead as they will never recover and some are in the verge of dying any time soon. So, in case you do not know, I guess you should be careful the kind of altcoin you invest in.
That being said, not all altcoin will survive obviously, but some will have a pretty good life as people start making use of their products in reality.