I am bothered by how "discrimination" has become an inherently offensive word. Choosing an employee among many is by definition an act of discrimination; what matters is what you base your discrimination on - whether it's something relevant to their role or not.
Mere lexical conservatism? Not quite. Policy discussions should revolve around which type of discriminations are permissible and which are sufficiently harmful that they should be banned; but the "discrimination = bad" has made this step all but impossible.
Hence you get people honestly, and correctly, arguing that to favour younger, or older, people is a form of discrimination. But then, rather than asking "did this employer have a legitimate reason for preferring a particular age group for the job?" (hopefully followed by "is it going to be harmful if people keep doing it?" and "do we have the means to stop it?"), they just slap the label "ageism" on it and are convinced that they have just proved that it's a Bad Thing®.
Let's say you are interviewing a candidate for a job. In casual conversation, the candidate mentions that he is a member of a rather old and prestigious country club. You've never heard the name of the club before.
You look up the country club afterwards, and are surprised by what you read. The club refuses membership to homosexuals. It revokes the membership of couples who use birth control. Leadership positions are reserved to unmarried males.
The candidate is otherwise competent. Under what conditions would you hire him? Would you want a law passed banning hiring discrimination based on country club membership?
(The country club is analogous to a nicer version of the Catholic church. I left out a couple bad things.)
Religious discrimination is illegal in many parts of the world, and I think that's probably a good thing. Still, keeping this at the object level (no meta-rules or veils of ignorance) it seems to me that discriminating against religious people is fine. I'm curious what other people think.