It goes without saying that BTCs dominance on the cryptocurrency market is very significant and has a lot of consequences like negative and positive ones. Even to take in attention the fact of BTCs being close to be the foundation of cryptomarket, it is very important influencer and it can be the reason of markets decreasing or its death in the worst situation. Thanks to this dominance alternative cryptocurrencies are not able to grow in their whole potential so cryptomarket cant be developed at all. From the other side of this question BTC has become the main reliable coin for investments and its stability is very nice for all of us. So is it necessary to have this dominance or it could be liquidated and with such methods? 
There is a possibilities that another cryptocurreny to be dominant just as bitcoin does, but it would takes so much effort to do that, cause people tends to keep looking on Bitcoin before they look on another cryptocurrency. Perhaps it's just mindset that makes bitcoin dominant to the altcoins.