I don't think these examples are good support
They are not support, the are examples. I am not trying to persuade you to start worrying, I'm explaining my position.
what you disapprove of here may not be only enforced politeness-and-decency
Well, yes, of course. I've been trying to generalize the issue out of the intently-peering-at-the-genitals niche. Yes, I would feel similarly about a mixed-race couple.
If such discrimination were legal, then people belonging to these groups might find themselves at a substantial systematic disadvantage;
I think you are mistaken about that. There is a fair amount of literature on the topic, but let me make two brief points. First, baseless discrimination is market-inefficient. Even besides potential social backlash, if you refuse to serve a portion of your market and your competitor is fine with it, guess who has the advantage in the notoriously ruthless darwinian capitalist world. Second, take a look around. Imagine that it becomes legal for store owners to discriminate against, say, Indians and Pakistanis. What proportion of stores do you expect to put up signs "No Paks allowed" in their windows?
The second example (Brendan Eich) concerns social rather than legal mandatoriness, and I think this is something that varies considerably between different bits of society. E.g., the owners of Chick-Fil-A and Hobby Lobby have espoused attitudes exactly opposite to the ones you say are becoming mandatory and they are at no risk of being ousted for them.
I'm not talking about the sign of the argument to the function, I'm talking about the nature of the function itself.
Owners of Chick-Fil-A do not (as far as I know) have an ideological litmus test that must be satisfied before allowing people to advance to high positions in the company. Mozilla, evidently, does. A great deal of the US academia, to pick a relevant example, does, too.
My concern is with intolerance, not with which particular sin is deemed worthy of excommunication and burning at the stake.
Owners of Chick-Fil-A do not (as far as I know) have an ideological litmus test that must be satisfied before allowing people to advance to high positions in the company.
I very strongly suspect they do, and I think you should assume that expressing the wrong political views can disqualify you for advancement in any given company. Though usually (I hope) this is less of a deliberate litmus test and more a requirement that "leaders" avoid "drama". Being feared or loved can be nice, but if your plan is to take people's money you want to be invisible.
There are some long lists of false beliefs that programmers hold. isn't because programmers are especially likely to be more wrong than anyone else, it's just that programming offers a better opportunity than most people get to find out how incomplete their model of the world is.
I'm posting about this here, not just because this information has a decent chance of being both entertaining and useful, but because LWers try to figure things out from relatively simple principles-- who knows what simplifying assumptions might be tripping us up?
The classic (and I think the first) was about names. There have been a few more lists created since then.
Time. And time zones. Crowd-sourced time errors.
Addresses. Possibly more about addresses. I haven't compared the lists.
Gender. This is so short I assume it's seriously incomplete.
Networks. Weirdly, there is no list of falsehoods programmers believe about html (or at least a fast search didn't turn anything up). Don't trust the words in the url.
Distributed computing Build systems.
Poem about character conversion.
I got started on the subject because of this about testing your code, which was posted by Andrew Ducker.