However, the hostility that you mention comes from the fact that the promoters/camps of these alternate implementations are still trying to proclaim that they 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.
In other words, the forkers want to take control of the rules but keep the name (and value - that is, users, and market cap) of something that was built without them, in a different way, with different expectations: namely, that no single entity of trust of a few entities could take control.
The problem I have with this is that the present coven has only one objective in mind: the maximization of short-term miner profit. If this is good for the hodlers, the casual users, or other investors, is immaterial in their agenda.
An example: in due time, they could figure out that a hard cap on inflation (the "21 million" ceiling) isn't really necessary to maximize their SHORT TERM profit. They can sell the block reward before the inflation is "felt" elsewhere, or before it is fully felt anyway. Which means an increase in profit: the full reward, or the part of it that hasn't yet been discounted by the market as inflation.
Another example: censoring or reversing transactions that they don't like. When mining is really centralized, and miners make the rules, that's entirely possible. Therefore, by Murphy's Law, it
will happen sooner or later. You want to send btc to some Chinese colleague of Assange's or whatever? You can't. You want to order a 1M$ mining rig from that rival of mine? Sorry, the transaction will never make it to one of my blocks.
I guess I could figure out better examples, but I hope you get the point. That would be the end of bitcoin as we know it.
I.E., - quit forking Bitcoin just to make a political statement or to gain more centralized control. It won't work.
Amen.