I still think that its a matter of a word, nothing more.

People say baduk or go, why?
People say goban or go board, why?
People say kifu or game record, why?
And does it matter?

For whatever reason the informal games are called "casual" games.
Do you really think it is worth to make a fuss over that?

If you can show that the word has some negative effects on something, acquisition of beginners for example, then you might have a point. Otherwise, it is just some little thing that everybody is ok with but for some reason it bugs you personally. I'd say - get over it, it is really not very important.

Well, I just think that people playing online seem to prefer(if not preferring, at least being accustomed to) a less casual style of play, why wouldn't that also be the case in person.

Bantari's point was that you can't just infer from the use of the word any particular or significant consequence. So unless you've played most of these people and thus have empirical evidence that they prefer a "more casual style of play" (whatever that is), it's bizarre that you're getting worked up about it.

I'm starting to think casualness is bigger problem than just games...

Like casual thinking?