Given the nature of human interaction, it's impossible for everyone to agree on likes, dislikes, or even what's deemed socially acceptable. For better or worse, there's always a chance that what you say or do will be taken the wrong way by your peers. And that's not always a bad thing, but it can cause distress when you discuss popular media. Movies, in particular, are perfect to learn about what was deemed acceptable in previous decades that may never have gotten the green light today.
Of course, the past is the past and we can't go back and change it. So we have to accept that it was more enjoyable to watch a movie or listen to music from our past when we were happily unaware of larger issues. Ignorance is bliss, right? Some people consider certain films to be so outdated that they shouldn't qualify as entertainment.