I think the reason the parent poster rendered that opinion has to do with the calculus - real or imagined - that stands behind Apple's particular choice of things to reject, and the common attributes that unite the sort of thing they tend to reject. Or, at least, the stuff that's made the headlines lately. It seems to have to do with things that allow you to use their devices more "freely" and/or do more and/or access more.

I don't think "censorship" is quite the correct term for that, but you can see where the idea arises that Apple is not just acting as a retailer that wants to sell certain products and not others in its store, but specifically wants to limit products that have to do with openness of information and freedom of use.

Whether you agree with that assessment or not, that's what drives people to use terms like "censorship" to describe it.