Devils advocate: you have to pay a top exec more if the company looks like its main product is in decline. Plus 2.4m/year isn't crazy in the scheme of tech salaries - that exec could potentially take other roles that pay even more.
Alternative: move the HQ and most development to Europe, where these ridiculous salaries are not common (see the example in the article of The Guardian boss), but there is still a strong privacy culture.
SV companies relocate development but never the top brass to Europe as they would lose their pay, status and network.
Believe it or not, just like with dating and real estate, your monetary value is more dependent on where you are rather than how good you are. Shocking, I know.