Not quite, THE most important advantage of Bitcoin over any altcoin is the huge leap ahead in market size, acceptance, recognition, branding, user base, everything. That's not some technicality that developers could decide to enable or include, recompile, release an update, and there it is. This takes years to grow, and Bitcoin has done this unlike any other altcoin.
Your original statement was that all altcoins are, apart from small technicalities, a copy of bitcoin. Some of them are not. I agree with what you say now, but this was not your point.
Does the majority of Bitcoin users think that PoS is better than PoW? I doubt it (I, for example, don't) and thus, it shouldn't be implemented in Bitcoin.
I hoped you'd say that. That's excatly the reason why bitcoin will not change much.
Please answer me this: If in an utopian world, there existed a PoS system that was able to reach fully decentralized consensus, and was not susceptible to attacks (like stake grinding /N@S), and had a good enough distribution, what would speak against a switch to PoS?
Would it not save a shitload of electricity being converted to heat? Would it not decentralize the block generation process, that is now in the hand of 4 mining pools (>51%)
hint: I'm convinced that this utopian PoS system already exists (not speaking about one coin specifically)
In the end, maybe Come-from-Beyond is right. Most people don't care about technical features, concepts like decentralization, block confirmation time and stuff. They just want to send or exchange money fast, or store it in a bank for convenience. Sadly this is why the world could just end up using ripple.