Like all products, Firefox still maintains a small core of uncritical, devoted fans. To them, Mozilla can do no wrong.
The problem is, up until a few months ago, Mozilla advocated for privacy and other public facing values that lined up with their manifesto. Now, they are breaking away from that, and the true believers are shifting too: becoming hostile to privacy.
The people who liked Firefox because of its privacy stance, or because they were looking for an alternative to Big Tech, on the other hand, aren't 100% likely to become a true believer, and those people are the critics. Often, those critics have been around for years going on decades.
I see this as revisionist history. Mozilla has long been beloved for a whole host of FOSS reasons, that align with the same reasons FOSS enthusiasts like anything FOSS. I do think there are fanbases for things who think their object of adoration can do no wrong (e.g. Sneako fans probably). They are out there, but I don't see that as being true of Mozilla.
I've seen supporters of Mozilla make nuanced points about it being an imperfect but important diversification of options that prevents Google from dominating the browser space, often in thoughtful interactions with fans of (say) the Brave browser or Opera browser over the fact that they rely on Chromium which is sustained by Google.
Those convos have more going on than uncritical adoration, and imo it's important to let those nuances breath so that they, rather the oversimplifications, can be our primary takeaways.
Interestingly, while talking in mournful past tense about Firefox's having lost their way, in this same thread there are people a few comments above denying that criticism of Mozilla is prevalent here. You guys should scroll up (or down) and say hello to each other.
We aren't fickle. We adhere very strongly to our principles but it's easier to direct people to a name when they aren't interested in understanding why.