Discrimination isn't subjective, either something is discrimination or it isn't. It would require cognitive dissonance to be someone who is opposed to discrimination while holding a personal belief that supports discrimination.

There is a difference between respecting your freedom of choice and respecting your actual choice. If your belief is repulsive to your peers and discriminatory then you need to realize there are going to be consequences for holding that belief and acting on that belief when it comes time to try to fit in with society. Your freedom of choice does not give you freedom from all consequences of that choice. On the other hand LGBT people are NOT free to choose to marry the person they wish if laws like the one Mr Eich supported exist.

If you stand against discrimination and apply social pressure to the people who choose to continue to support discrimination then you are, in fact, on the side AGAINST discrimination.

It is a curious characteristic of the philosophy of tolerance that only one thing may not be tolerated: intolerance.

In general, I don't like a sociocultural norm that punishes people solely for taboo or unpopular beliefs; while I'm pro-gay-marriage, I hold other opinions which are even more controversial. Yet if the issue was a more extreme one (say, if Eich was a Holocaust denier), very few people would be comfortable with having him in a position of power, and the implicit legitimization of that political opinion.

I'm not sure it was right for the left to call for his resignation; however, in terms of what's best for Mozilla and the open web, I think it was the right move for Eich to step down.