Being tollerant towards intollerant people, hasn't worked out very well as history tells.
Extremists will at any time cry foul that some people are intollerant against them, but at the same time perfectly realizing that they were intollerant in the first place.
But if he is activly anti-GBLT his smell and his taste will at one point or another stain Mozillas hiring policies because what the boss says goes, even if it's "private". It's unavoidable and this is bad.
And that is why such a person should not have become CEO of a "colourful" company in the first place. However he should be free to tell his oppinion on LGBT-people, but he should tell it honestly, not the soft washed terms, "think of the children".
He should express his true believes: that he hates LGBT people and thinks that they commit to soddom & gomorra, and that HIV is a devine punishment and that LGBT people should rott in prision like in Uganda because they taint the souls and make other people gay. And that sticking the penis into the ass of another man is dirty and annatural because sex & lust are only ment to produce children so all other uses of the tools is praying to satan.
Most homophobics men fear to see naked men because someone could spot the increasing VECTORSUM.
If he becomes CEO of the Church of the first saints and nostalgics, so be it.
But for now should step down, and a shitstorm is the best way to overcome such a person.