I don't know who YOU were watching, but I didn't think Jenna and Barbara were either classless OR disrespectful. They poked fun at their parents and grandparents, but it was in a loving way, and I believe most everyone, except a few folks here, understood that. They are VERY close to their Mom and Dad and to Poppy and Bar. Barbara said once that Poppy used to write them letters all the time, but he's since discovered e-mail and keeps in touch that way. I only grew up with one grandparent, all the others had died by the time I came along, but I felt about her the way the twins obviously feel about their grandparents, and it's fun to see families that still interact that way. I think they are an ASSET to their Dad, the giggling notwithstanding.
Thank goodness for Republicans that the only thing I hate more than humorlous moralizing prigs is liberals. The folks who think that what Jenna and Barbara did was out of bounds have no clue what class is. Using intergenerational stereotypes to have a bit of fun hurts absolutely no one - at least no one with any sense of self-worth.