Any time any large company takes on a new emotional or social posture, there is legitimate concern that it's just pandering and manipulating for business motives not social ones, and has little to no actual value to the concerns of your supposition.

Also, Mozilla is a technology company, and the technology itself is mostly oblivious to social issues (unfamiliarity with UI metaphors being the most obvious barrier), so it comes across as a distraction in terms of effort, which is especially concerning to donors.