Why are altcoin exchanged for btc and not for dollar?
having tons of altcoin is just like having bitcoin. If bitcoin grows, they grow. If bitcoin falls, they fall.
Isn't this pointless? Why not buying and selling alts for dollar?
Because dollar doesnt fluctuate,bitcoin and altcoins does,that is why you shouldnt be using any of these fiat currencies as they are controlled by the banks/governments.Cryptocurrencies are decentralized and it is the future currencies of our generation which is why those adopted these currencies are going to be wealthy in the future.