Just guessing, based on HN groupthink patterns:

1. that tax return shows the former CEO was paid almost 7M annually

2. sharing that on this post, they are probably insinuating that it was a mistake for Mozilla to pay their CEO that amount just for them to lose so much marketshare that they're now nearing an inflection point

The inflection point being where a negative feedback loop starts: FF loses marketshare, devs stop testing against it, sites break for users, users leave FF, FF loses marketshare, repeat

This post in particular shows that there are breakpoints where government and government-adjacent entities have policies stating that they test against all browsers with > some % of marketshare.