The man that donated $1k to ban gay marriage in California became CEO of a progressive company in a progressive industry (American tech sector in general). He's otherwise highly qualified, because he invented Javascript and co-founded Mozilla, but he's apparently anti gay rights.
A number of employees publicly disagreed with the CEO choice because of this. Mozilla offers same-sex health benefits to employees, so it would indeed be kind of alarming if you or your co-worker friend is gay and works at mozilla, has gay spousal benefits, and the new CEO is known to have contributed to an anti gay marriage political campaign. For example, the company Mobil had gay spousal benefits but then Exxon acquired them and cancelled them. So they can be lost. I think in states where gay marriage is legal, companies have to give same-sex couples benefits now, though. So that might be less of an issue. But in general, it's reasonable that employees might want want someone with those views being the primary public face of their organization.
Three directors left the board when he became CEO, but the company states two of them were planning to leave.
Then OKCupid did that boycott, and so in addition to the employee remarks and articles about the board, it all went very public.
Eich said he wouldn't leave, and the next day he stepped down, so the board must have fired him.
What's interesting about this, is that apparently it's at the point where in this industry, it's so socially unacceptable to be anti gay rights, that you can lose a high profile job over it. Of course, anybody who has donated to an anti civil rights group, or has donated to a campaign to ban interracial marriage, in any industry, would be kicked out with little public debate about the issue, because those things are extremely socially unacceptable now and would be terrible for company image.
So, just like some companies wouldn't want a CEO in favor of racial school segregation back in the 1950's or 1960's (and now all wouldn't), and just like how some companies wouldn't want a CEO in favor of banning interracial marriage back in the 1970's (and now all wouldn't), it's reached the point where some companies don't want an anti gay rights CEO in the 2010's.