If you realize why XT, Classic, BU, BCash etc has failed [...]
They haven't and are still around. It is not a game about total dominance. The hostility towards other implementations is beyond me. Again diversity is key for trying to achieve some level of antifragility.
[...] Core's roadmap is the best possible solution [...]
I will let the market decide, thank you.
Yes, you are correct that the market should decide what the majority consensus implementation should be.
However, the hostility that you mention comes from the fact that the promoters/camps of these alternate implementations are still trying to proclaim that their forks or implementations are THE ONE AND TRUE Bitcoin, when clearly they are not. Not by longest chain. Not by most popular support from users, merchants, brokers, and exchanges. Not by most mining support. Not by most hashrate. Not by any
measure whatsoever.
So the hostility is aimed at their misguided promoters, not at the implementations themselves.
I.E., - quit forking Bitcoin just to make a political statement or to gain more centralized control. It won't work.