> Imagine that c-suite types may just work for the salary, too

That's fine, and if people decided that, I would respect that decision. In which case they could resign, and Mozilla get people willing to work for $500,000.

> hey engineers, how about cutting your salary to $60k?

The problem is you might severely limit your talent pool, to a much greater extent than a cap of $500k would do.

> If you think $60k is too little, ask your colleagues from EU, from India, to say nothing of Africa.

Maybe Mozilla should hire more people in those places, if they need to do so to save money.