LOL, this makes no sense. and there is nothing to back that statement.
What looks unprofessional about any phone... is using it when you shouldn't... If any phone looks unprofessional, it is the Galaxy Note just because it is huge.
ADDITIONAL: There was some phone a coworker of mine had that had a screen that is bigger than the Galaxy Note's Screen (he had it before even the GS2 was out). It actually looked like a tablet and not a phone. I can still remember thinking how stupid he looked using a phone that was bigger than his head (almost literally)
ADDITIONAL 2: The screen size may not have been above 5.3" (G Note), but the total size was bigger. The only thing I remember about what phone it was, is that I had never heard of it before, which is why I can't remember.