I do not think Bitcoin needs altcoins. Each altcoin brings different innovations. But as a payment system, Bitcoin already meets our needs.
Even if there is no altcoin, bitcoin will continue to exist in the population.
Altcoins are good competitors to Bitcoin and I think it just needs it. All of them were created on bitcoin's base and I think one of them can take the place of bitcoin one day.
I am disagree. I think bitcoin can be on the top without altcoins and all of them are weak competitors which not affect on bitcoin's price at all. If altcoins will disappear bitcoin users will not even notice that. Nothing will change. That's right that all of them just want to repeat the success of bitcoin, but I doubt that any of them can fly so high indeed.