There's something about this specific part that doesn't sit well with me.

It's like justifying a huge salary for the president of a charity because they receive millions a year in donations and revenue from charity shops... it's just wrong.

7 million (assuming that's the correct value) is a lot of money. Perhaps not as much as they'd make at Google, but a lot of money nonetheless. And Mozilla is supposed to be a non-profit, with a good mission, with a manifesto, in a David vs Goliath struggle... but the CEO still makes millions, even when cuts are being made those working on the main mission?

The bar for Mozilla is different because they present themselves as being different. Multi-million salaries is what you expect from regular companies, not from good non-profits, and I think that's why the CEO's salary always comes up in these discussions.

With all this said, I also agree with the point about some of the criticism. Nothing Mozilla does pleases everyone, there's always something. It's a hard position to be in.

No, people are saying that Firefox needs to diversify their revenue streams because almost all of their revenue comes from their main competitor who (likely) only keeps Firefox alive to keep regulators from forcing them to divest their browser. The situation has gotten more dire since the regulators got fired last year.

That's the problem. CEOs get paid so much more than everyone else while typically not providing value commensurate with their pay.