If you believe something else is being snuffed out, it would help to mention what it is so people can help you. Because making that statement without context doesn't really stand alone, it's also just noise.
And in the case of vendors who haven't...?
You say that such complaints are just noise to Google because they have already acted on these complaints (ie, Pixel bootloaders are unlocked). On that, I think you and I agree re: pointless complaining.
I'm asking, why not continue to complain in an effort to push vendors with locked bootloaders to unlock them? Specific vendors are irrelevant, I'm just curious if you do/don't think people should complain to them, as well.
My comment is not about specific vendors and their actions. My comment is only about wondering when, in your mind, is a valid time for people to complain; a philosophical question. That's why the question is broad - is it OK for people to complain about vendors who have yet to take action?
Your comment just now suggests that, yes, contrary to your post complaining about complainers, you likely think it's fine to complain to/about vendors who haven't taken action you'd like to see taken.
Edit: Your logic in the last paragraph doesn't follow to me, as I was responding to a specific complaint. So that's another reason I can't really give an answer to the question.