Of course they don't care. But you can feel the experience is not spotless.

I usually don't notice or care, unless they haven't put any effort into it. Now that I'm thinking about it, there are a few that I suspect aren't native, and I don't get bad feelings from the apps unless they are badly programmed and the functionality doesn't work.

But if they don't care, why does it matter what they feel?

What I mean is they don't actively consciously care. They have better things to do. But they're not immune to perception. They do have some impression and experience that they're also likely to be able to express in the form of feelings.