The article contains counterexamples. You can start from those if you really think they're not reasonable (i.e. the answer is never)

You're mistaking a claim that a group of people based on their ethno-religious background is either worthless or to be blamed for multiple world issues (which historically led to killing them) with an opinion we can be respectful about.

I wouldn't expect you to be respectful of their opinion should it ever turn up in the course of your dealings with them as part of engaging in the community. But if it doesn't come up, you have no cause to be exclusive to such a person.

The pilot's opinions are a perfectly good example, must communities shun that airline as religiously impure if an individual pilot disagrees in any way with current authoritarian enforced doctrine?