Just because someone believes in something doesn't mean everyone else has to respect that belief, it works both ways. Fact is being publicly anti-gay has become socially unacceptable and Eich has chosen to do things which upset pro-gay communities so they decide they do not want to have anything to do with him. Simple freedom of speech.
Being "tolerant or open minded" of things like gay rights for example doesn't mean you can't be intolerant towards people against that position. You could say that someone can be tolerant of everything but not only is that rather unrealistic but it's not OKCupid's position to begin with.
EDIT: However, Mozilla claimed to be open of all beliefs and they should have stood their ground instead of flip flopping. Like I said before it's a radical position to keep in the first place but they should have expected it and should have been prepared to deal with the consquences, instead of firing the guy.
