Why bother having a thousand currencies when one will do? Many people that use bitcoin already have multiple wallets, who wants to keep track of more, and what service would it serve. Even if it were all automated in a single wallet app?
It takes quite a bit to become accepted by merchants.
It's true. The adoption for BTC is huge right now compared to other currencies. Even though it may not be the best, it is the early adopter and wins on the acceptance front. Until there's an easy way of converting BTC into other crypto currencies, or being able to buy in different currencies similar to fiat currency, then it'll be difficult for other currencies to survive.
Right, and if other currencies bring something that is found to be essential to the future of crypto, bitcoin can update and use it.