> ... why don't they support worthwhile OSS efforts ...
They do:
"Mozilla Open Source Support (MOSS) is an awards program specifically focused on supporting the Open Source and Free Software movement, with an initial allocation of USD $1 million."
They do:
"Mozilla Open Source Support (MOSS) is an awards program specifically focused on supporting the Open Source and Free Software movement, with an initial allocation of USD $1 million."
https://static.mozilla.com/moco/en-US/pdf/Mozilla_Audited_Fi...
Interesting detail about Yahoo:
"In December 2014, Mozilla entered into a contract with another search engine provider for royalties which expires December 2019."