I never got the vibe that "IC" was intended to be dismissive, or intended to be a pejorative or anything. I think it's more of an HR thing, because the distinction between IC vs Manager usually affects compensation and blah, etc. Whether or not that should be the case is a separate question.

I always assumed the term just leaked out of the HR world and into the general parlance.

It depends on the culture setting.

If you're in a place where an IC can potentially make half a million or million dollars a year and drive some very interesting project work and be highly respected, no.

If you're in a place where not making it into manager track puts a very low ceiling on earning potential and respect, then yes it can be condescending.

This varies a lot by country, industry, etc.

I think you're projecting

I've never heard of someone not liking the term "Individual Contributor" before