In class we were supposed to use half salted half unsalted. I never have unsalted and always go full salt and find it just a bit TOO "salty" you know? But people seem to really like it because everyone I know seems to like things a little less sweet. Entirely unsalted just results in a really bland buttercream.
The only other kind of frosting I'm familiar with is the kind you buy in plastic containers. Or that awful stuff on grocery store cakes that must be entirely shortening because it's so waxy and gritty. I have been known to eat straight out of the plastic frosting tubs though lol. I definitely don't do that with the imbc so I can see where you're coming from.