Bitcoin will be the king of crypto currencies for years to come,but there will be certainly space for other good coins in the market, coins like Litecoin, monero and Etherum has a lot of users and have a maket value, but i dont think so it will cross bitcoin for now,but anything is possible in the future ,you never know life is unpredictable.
That is just an alternative currency and a lot of their users is a trader and finally, if we get a profit in there and the ending they're wanna for exchanging their coin into bitcoin... they are wanna for using another coin like monero,LTC and ETH is caused by bitcoin.