Making the product worse, from the perspective users care about, for ideals.

FF, for instance, made their multi-browser "sync" horribly complicated for users, to preserve zero knowledge, which is the opposite of what 99% of users wanted.

Chrome made it simple (and THEN added a fairly decent ZK option buried in advanced).

What makes Mozilla/Firefox relevant is having enough users that it can't be ignored. Mozilla is already increasingly irrelevant due to mobile (Firefox OS is nice promise, but Safari and Chrome are dominating the space); marginalizing their desktop product doesn't help.