That's a common belief, but quite false. See Wikipedia:

http://en.wikipedia.org/wiki/Dodge_v._Ford_Motor_Company#Sig...

I believe the requirement to maximize profit is a requirement of the stock exchanges, not a requirement of being a company.

A company can be created for many different purposes.

Can you provide a link to the law that says a corporation must maximize profit even when it's against the desires of its shareholders?

Even if that were true, only the shareholders would have standing to sue them for failing to maximize profit. Clearly the only shareholder, the Mozilla Foundation, is not going to sue Mozilla Corporation for doing what the shareholder wants it to.