Some movies are beloved by fans when they come out, but as time passes people start to take a more subjective look at the film and realize it wasn't quite as good as they originally thought. There's plenty of reasons for this and some are pretty easy to spot:
Avatar was a beautiful movie, but when it isn't right in front of you it's much easier to realize it's a pretty lackluster plot about Unobtanium miners. Smokey and The Bandit is about Burt Reynolds driving around and being creepily 'charming' to women, but you couldn't get away with making a Smokey and the Bandit movie today.
Sometimes there's a quieter, more nuanced realization about just why a movie is no longer popular. Whether it's the fact that somebody behind the film, or starring in it, turns out to be a rapist or maybe society just changes and the movie no longer becomes as poignant, or acceptable, as once was. Can you imagine a movie made post-9/11 about an American helping out heroic Islamic holy warriors?
Look at The Matrix - once upon a time it was untouchable, but now there's a thousand articles on the net devoted to how stupid the idea of 'human batteries' was.
10. Rambo III (1988)
First Blood 3: Rambo Wrecks Russia - or as the film was actually called, just Rambo III. Sylvester Stallone's eponymous PTSD-addled hero is brought out of retirement in Thailand by his old friend and mentor, Colonel Sam Trautman to aid the Afghani people in stemming the Soviet invasion.
Rambo claims he's tired of the fighting, but after Trautman is ambushed and captured by the Soviets, Rambo undertakes a solo rescue mission to bring him back home. Rambo must ally with the resistance fighters, known as the Mujahideen. After working alongside them to rescue Trautman, the original movie ended with an acknowledgment praising the gallant Afghani people.
So what makes it age so badly? The Taliban. You see a Mujahid is an Islamic person who is engaged in Jihad. While technically a Jihad is any type of struggle one puts forth in making themselves or the world better in the eyes of Allah, it is most often associated with Islamic Holy Warriors.
In post 9/11 America, it is very difficult to recover in many peoples' eyes from being allies with the same people responsible for the World Trade Center bombing - for instance, several articles praising a proud Mujahideen named Osama bin Laden made the rounds in the '90s.
The existence of a screenshot claiming that the original wording of the ending card was "This film is dedicated to the brave Mujahideen fighters of Afghanistan". It appears to be a doctored photo, but it hasn't helped to stem the criticism of Rambo working alongside potential Osama bin Laden-esque characters.