Sometimes I wonder if it is because a player can't resist saying, "I had it" or "I bluffed your butt". If a person does it a lot, it does seem amateurish. Other times, I think about whether this is strategy, especially if it is more selective; but it depends on the player. I see how it might be seen to some as another strategy, but I wonder if anyone has really written an article about this...probably somebody has.
There are times when you are playing tight, but get a run of incredible cards and the hands don't go to showdown; as a result, you could be seen as loose. I am interested in this case to what people think of showing and how it relates to perceived tendencies by others at the table.