Right now, changes to the consensus rules can be blocked by lack of miner agreement. I think it would be better if they could also be blocked by lack of programmer agreement (i.e. an outside team refusing to update their implementation).
Arguably that's pretty much what happened during the hardforks of 2017. The scenario you describe is less extreme, of course, but in the end that would be the logical conclusion.
I'm aware that this would make implementing new features (especially controversial ones) nightmarishly difficult, but (in principle) I believe that's a good thing.
Obviously, any idea that leads to a glacial pace of feature development is not going to be a popular one, and I'm mostly just fantasizing out loud at this point

Compared to most alts Bitcoin's development already
is moving at a glacial pace

And for good reason! But I fear increasing the political overhead would pretty much halt development and possibly even increase developer attrition.