Earlier quoted context omitted.
I agree. I would rather pay them some fee. But they don't seem to want to monetize their service via user fees.
Seems like it would make a lot of sense for them to offer both options; either would discourage bots, and you'd give people the choice whether to go the free route or the privacy-conscious route
And accepting a cryptocurrency would probably have little impact on all the lucrative scams that get spammed around Twitter.