I don't like non-crusting.
With my crusting BC, I wait a few minutes for it to crust over. I then pipe on my lettering. If I make a mistake it lifts right off without much, if any, damage to the icing. I can lift off most decorations without have to re-ice the cake.
I can also lay chocolate transfers onto the cake and lift them off without sticky icing all over the backs of them, unless I have pressed it into the cake.
I like they look it has when it dries.
I just like it better. But it's a personal thing.