I use a butter bell and would not otherwise leave my butter out on the counter. Maybe it's a climate thing (living in Louisiana and Houston most of my life where it is hot and humid 9 months of the year), but I don't think I know anyone who leaves butter out.
I would consider using a butter bell to be leaving it out (i.e. not in the refrigerator). You say you don't know anyone who leaves butter out, but (to me) you do. Perhaps different posters are defining "leaving out" differently. I must be confused or just missing something.
