the only great thing about it is that the alts will be allowed to siphon all the value out of the Bitcoin MC. great for alt devs and investors, not for Bitcoin holders.
I don't necessarily agree, I believe Bitcoin will remain king, people will treat Bitcoin as the "central bank", where they hold their savings and assets, plus it will bring incredible functionality to Bitcoin. Think about a killer sidechain feature that brings in 1 million new users, that is a good thing. We are far too small of a user base to think about limiting options, and I believe sidechains could bring in a lot of new people, which is what we need.
I know it's a really tired argument and I agree with a lot of things you say, not trying to ignite another debate.