[darshan]

Telling someone "this isn't interesting to you" in place of "I don't want to talk about it" is definitely not polite!

I'd say it's rude in general to tell someone they won't find something interesting, and especially so when it's done as a way of disowning your own preference not to talk about it.

[kbenson]

There's way too much being read into a statement which begins with "likely". There are plenty of things in life that are hard to explain in a way that doesn't lead to misunderstandings which are also not very consequential.

For example, when people ask what I do, I could say I work at an ISP, or that I'm a systems engineer (my title), or that I'm a system administrator (some of what I do), or that I'm a software developer (the rest of what I do), or any number of other things. Depending on how interested in it I think they will be, or how interested in explaining it I am, I might respond that it's likely not that interesting.

If the person asking actually wants to pursue it further, the polite thing to do would be to say "oh, I find it interesting, if you're willing to talk about it". If they responded "How do you know what's interesting to me?" I would take that as somewhat aggressive, and definitely wouldn't be interested in explaining further, depending on how I perceived their disposition.

Perhaps it's a cultural miscommunication.

[Dylan16807]

That phrasing (at least without the "to you") is fine when you are genuinely open to saying more. It's not fine as a way to refuse to say more. So you're talking about a completely different context.

If they get aggressive and you then decide that you don't want to explain, that's fine. But that's not what happened here.