HN is a community. Users needn't use their real name, but do need some identity for others to relate to. Otherwise we may as well have no usernames and no community, and that would be a different kind of forum. https://hn.algolia.com/?sort=byDate&dateRange=all&type=comme...
If you were using Chrome before, Mozilla was around before and their motivations were the same: why did you switch to Chrome in the first place? I'd imagine the motivations there are the ones that are most common (after all, Google ended up eating Firefox's and IE's lunch somehow).
> but how many users are going to be motivated by that to move the needle
1 is enough to disprove "Nobody is going to switch from Chrome to Firefox if the UI is radically different" which was my point. zazaraka is projecting their displeasure on a lot of people.