I can see someone like Stephen King being annoyed at having to pay anything when his presence is probably helping Twitter quite a bit to begin with.
[EDIT] My point is, from King's perspective, this likely looks like "you're here and making $X over what you would if you just relied on your fans to repost all your stuff on here for you, we're making $Y more than we otherwise would because you're here, plus we've given you this blue-check thing to solve a problem we have, but now $Y isn't enough and we're going to make you pay money to keep participating in this program that exists to solve a problem for us."
You can see how, unless $X is pretty big, someone who's already rich might say, "well fine, fuck you too" over such a thing.
That may have been true at one time, but I'm not so sure it is any more.
Thing is, the "blue checks" aren't all Stephen King level famous. If you're doing much notable at all, and using the platform, you've probably got a blue check. I do not, for the record—I'm not sure I even have an account?—but I see an awful lot of them on fairly niche but interesting & active personal accounts. Take them out and the best content goes back to being "I'm a Twitter Shitter!" kinds of stuff, like in the very early days—and the novelty for that is long gone.
If these posters stay but let their blue checks lapse, we go back to having an impersonation problem, which is mostly a problem for Twitter, which they may want to solve. Perhaps for accounts that are likely to be impersonated they could introduce some kind of free verification system....
They do, though. The premise is simply wrong here.