Hello, you might have read some things about this topic that aren't correct, because sadly the press has in general done a very poor job at fact-checking this story. Since you care deeply enough to send this message instead of silently turning your back on us, you might be interested in some attempts to clear up a lot of this misinformation:

Here is a short collection of facts about what happened: https://blog.mozilla.org/blog/2014/04/05/faq-on-ceo-resignation/ and here's a longer version written by an employee in a blog post: https://medium.com/p/7645a4bf8a2

Brendan didn't have to leave Mozilla - we would like nothing better than to rehire Brendan. In fact, we didn't want him to leave in the first place. However it was his personal decision to resign among all this ongoing frenzy, threats and mischaracterization of him as a person and the Mozilla community coming from third-parties, in order for the constant bombardment to end and to avert any further damage to Mozilla and its mission that he helped build for so many years.

So in this sad process we have lost a co-founder and brilliant technical mind and now the "other side" of the political spectrum comes along, again quite misinformed and rushing to judgement, bashing our community and voicing calls for boycotts against our products. This is quite sad & Mozilla has not deserved to be in the middle of all of this. Our community exists to protect the Web by promoting openness, innovation and opportunity and is no battleground to fight culture-wars upon...

Thank you!

Unfortunately many have assumed he must have been fired or forced out due to his decision to leave instead of going back to CTO or another role at least in meantime.