We were a cool whip only family.
My mom kept a kosher house, which on a simple level, meant you didn't mix milk and meat. Therefore, if we were eating turkey for Thanksgiving, we would have had to completely clear the table and switch the dishes (part of keeping kosher) before we could have desert. Because Cool Whip is non-dairy, she could serve that with desert with out the big dish change over, as pumpkin pie and pecan pie can easily be made non-dairy with margarine rather than butter.
and, i love frozen cool whip!