I suspect that it is difficult to make a distinction between "centralized" and "decentralized consensus forming."

Decentralization doesn't necessarily mean good decisions, just like democracy doesn't necessarily mean good decisions. Decentralization just helps us share risk.

It's not hard to imagine a decentralized consensus forming around something that you and I consider antithetical to Bitcoin (for instance, the jpeg people are somewhat decentralized).

My point here is not whether a soft fork is good or bad and I agree that we've had many soft forks in the past, but I want to point out that the mechanism is surprisingly similar to that of an attack.