You've actually hit on a separate, but related issue.

There is a subset of toxic people and petty tyrants among the core developers who believe that what they do defines Bitcoin and wish to be the eternal gatekeepers of what is and is not allowed. They can't actually earn that position by virtue of being superior software engineers, so they keep it by resorting to FUD and other underhanded tactics any time some other developers try to get involved.

There's an extremely long list of people who would have tried to step up and participate, but have been effectively shut out by that cartel.

Bitcoin will be in a much stronger and more secure position once Bitcoin Core is deprecated, or is at least relegated to a minority position on the network. Part of the reason will be that the consensus will be derived from software implementations with a better design and higher code quality, and part of the reason will be because of limiting the effect of toxic developers so that more people will be willing to contribute.

PS: I still haven't forgotten that you never bothered to justify your "less decentralized" claim about colored coins.