It's not just Twitter the company. It's often the users as well.

I've seen a bunch of people basically bent out of shape because Twitter essentially didn't see them as important enough, based on whatever arbitrary algorithm, to give them a blue check.

I was also turned down in spite of having an impersonation attempt (which I did get banned) and writing publicly on a regular basis. I didn't really care but I understand that some do. I doubt I'd pay a monthly fee so long as the site was generally usable.