While I agree they shouldn't be putting their money towards political causes, the scrutiny of the budget is also political in nature. Of the $400 million in expenses, only around $15 million went to executives, and around $1 million went to the DEI stuff. The rest was split evenly between developing and marketing Firefox, which is basically what you were criticising them on not doing.

If they got rid of all the executives and DEI, they could increase the other budgets by 2%. There is 0 chance that the 2% extra budget could help the market share and development in any significant way.

And if you don't pay executives enough, you get worse executives who make worse decisions because the good ones will go to other companies. So you'll be complaining even more if the $15 million executive pay got dropped.

So in short: I agree Mozilla shouldn't get involved in politics. Despite this, no reasonable person could look at the numbers and conclude it's having a material effect on the destiny of Firefox.