Three points:

  1. While not being as clinical or over the top as porn produced today, adult movies produced in this era still covered issues that you won't even see Max Hardcore address today. Porn actresses could (pretend to) be underage on camera, and sometimes you could even see sex acts between (actors playing) brother and sister or parent and child. Today, it is illegal to even simulate the depiction of underage sex. I do not know why the incest themes are gone, but I suspect it is due to a heady blend of litigation and complaints.
  2. Dig through the vintage bin of your used video store, and you'll find a bunch of "Golden Age"-era videos that are every bit as shlocky as what you can get from Leisure Time today. Especially annoying is the poor overdubbing done by some faceless voice talent that ruins most old scenes. Shlock is not bound by any era.
  3. Porn companies still make big budget movies geared towards couples (an attempt to draw in women is another change from the Golden Age flicks). Much like you would see with more family-oriented movie studios, these are break-even or even money-losing prestige pieces, whose costs are covered by the oh-so-important shlock. Vivid Video and Wicked pictures are especially known for this.

I will admit that I have a bias here. Personally, I would choose any volume of Shane's World over any Golden Age title. No, there is no plot or acting or film footage of any sort in the series, just attractive, fit people having fun and filming it themselves. More of a home brew than mass production.