Money. If they can get more money by cutting out some of the sex and/or violence to widen the appeal, they’ll do it. Hell they also offer “DVD only” releases where they add more sex and/or violence to some movies (mostly putting back in stuff that they had to cut in order to get the MPAA rating they wanted). The cuts of a film they can offer the wider the potential customer-base for their product – and at that level it’s all about moving product not creating entertainment (let alone any thought about art).

It doesn’t seem that much different from having an “edited for broadcast television” version of the film, except that they’re offering it for direct sale to viewers instead of to networks. In fact, I wonder how many of these are special edits for family viewing, and how many of them are actually potential/actual broadcast network edits that have been slapped onto the disc for sale?

(And actually now that I think about it, studios do this ALL the time. The entire MPAA rating process is all about finding that sweet spot for films and cutting enough material to drop your movie from an R rating to a PG-13 rating. This really isn’t all that different, except that you’re doing it to get at a narrower audience rather than at a wider one.)