People who call manga "comics" should not be associated with.
Sorry to burst your bubble, friend. Comics come in all kinds of forms for all kinds of people.
I kinda get what you mean like, there’s a reason we call manga “manga” and not “comics” because of the difference in culture and to be able to differentiate them. (Heck, you read them backwards, that’s a hard adjustment for new readers.)
Let’s put a western comic next to a manga. Batman and Ratman.
Obviously there’s a difference at first glance, but they’re both from the super hero genre and both have panels in a sequential form that tell a story from the hero’s point of view and that’s kinda the definition of a comic. (Well, except “comic” was taken from the word “comedic” and a lot of comics are anything but funny nowadays but that’s beside the point.)
Point is, yeah, there’s a culture difference so it’s easier to name them differently but in the end they’re both comics and instead of putting your chin up and saying “don’t associate with someone who calls manga ‘comics’”, maybe you should politely educate them that there’s some differences and you’d rather they not call manga “comics” around you. Because maybe they just see a series of panels on pages and know that’s a comic but don’t know the term “manga” yet and honestly, if you’re snooty about someone who honestly didn’t have prior knowledge and make a big deal out of it, there’s a huge chance you’re gonna make them hate it. Not everyone went through the weeaboo phase at the same time and you probably lost a potential good friend you could have recommended manga to.
(Also, you kinda sound like you’re badmouthing comics but have you ever read a Spider-Man comic because Peter Parker is hilarious ok.)
((Also also, western comics aren’t just Marvel or DC Comics. There’s a ton of really amazing individual comics as well. Here’s two my friend owns that she absolutely loves and promised to let me read. Please broaden your horizons or you’ll miss out on hidden gems.))