I think we're past this being a disrespectful thing, and it's just how society evolves. There was a time in which anyone carrying around a cellphone (the big, brick ones) were seeing as showoff.

And years ago, if you saw someone with one of those bluetooth "stalks" as you called them in one ear, talking on the phone loudly on the street, you would think "what a douche!" But today, it's so, so, so common, that nobody seems to care anymore, not even myself. Of course, if they're in an enclosed space, or a relatively quiet space, then that will always be annoying.

Do I like this new norm? Not particularly, as I'm old school. But I just accepted it. And there has been a few times in which I had to do it myself (e.g. talking to someone while carrying some boxes or solving a problem with my bank while folding laundry), and it's kind of relieving that I can do this without feeling ashamed - again, because everyone else is doing it.