FFmpeg open sourced their software for all to use without having to pay for it. This was a choice they made.
Then on their own web site, they only accept 1-time donations and state “If you find FFmpeg useful, you are welcome to contribute by donating.” [0]
Then someone comes along to donate (and play by the rules they’ve set), and they publicly complain about it?
Some Advice: if you want to monetize Fortune 500 use, don’t open source it. Or at least, create a strategy that allows you to monetize it (like what Sidekiq has done).