You are making excellent points. This is my criticism as well. Now there is real purpose/motive behind much of this stuff and that purpose is to make it mainstream and considered normative. There is a reason this stuff is being put in movies that are being marketed to children. I do, however, disagree with your comment that no innocent adult movies have been made in years. "Driving Miss Daisy," among others, was fine. Another, even with the adulterous scenario, was "The Horse Whisperer." I'm sure I could come up with others, but that'll do for now.
Oh, there HAVE been (IMO) "good" movies - esp. ironically in the "adult" realm. I've been to more movies in the last couple years primarily cuz I thought they mite not only be of interest, but mite not offend me. (I've been wrong sometimes, but generally I pick pretty well. ;-) )