Oh, there's no doubt it's not perfect - far from it. But back then we didn't notice or expect it to be. Some films were very realistic and gritty, you're right on with that. However, there was still an innocence that was genuine & acceptable. TV is a great barometer of the times as well.
To me, that was one of the things that was so shocking about Luke's burned family being shown. As graphic as those few seconds were, I think it would be a much harsher scene these days. Cop films - French Connection, Serpico ( a huge favorite), Dirty Harry, etc - had already made the jump to realism, but not at the level and frequency of today. Plus, those films were aimed at a different audience, not teenagers. A great deal of the world was still ok with innocent, happy ending fairy tales.
Besides - isn't our imperfect golden cow what we're all trying so desperately to get a proper release of?
;-)