Bitcoin have future thats for sure. I do believe that there will be some alts standing still not just LTC and ETH but these as well: DASH, DOGE, XMR, ZCASH
There will be more of them. But the point is and will stay prob most of the alts will exist in the future for the people to gamble upon, to create fake value. We all know that most of them were made for profit and nothing else.
Yes altcoin have future for sure there are a lot of altcoins that has good fundamentals and has been there in the market for a long time. Ethereum is the most common example of great altcoin that has future from fundamentals to investors to players it is well played coin even if its a hype sometime you will never know how far this could go but in the end it has a future.
many people do not consider ethereum as an altcoin anymore. Ethreum can perform better than bitcoin with it fast blockchain and the marvelous smart contract. Ethereum is the new revolution in the blockchain technology and soon people will understand how to use ethereum step by step and it will become the strongest currency on the world