I really doubt anything will come along that is considered "better" for everyone.  Anonymity, for example, is well below scarcity, security, and historical record on my list of priorities.  But the thing with SC as opposed to altcoins is that bitcoin the currency stays the same.  It is only bitcoin the blockchain that is in danger of being replaced.  And even if it is replaced, bitcoin the blockchain will still be mined heavily at least until the subsidy dries up because new coins can be moved to whatever chain is successful.

SC also provides a way forward scalablilty wise that doesn't require a VERY controversial hard fork.

In the end, any opposition is irrelevant.  This is a soft fork change, which means any single miner can choose to adopt it and remain compatible with the existing infrastructure.  Other miners won't add the new transactions since they are "nonstandard", but they will validate blocks containing them.  If use increases to the point that they are missing out on fees, you bet your ass they will jump on board.