1. It's a 70s movie, not everyone from the 70s is dead

2. Most people do care about respecting the dead. Otherwise there wouldn't be laws against desecrating graves

The director is 87 and alive. https://en.wikipedia.org/wiki/William_Friedkin

It's not "just time". It's the nature of copyright in its current form as well as a certain set of cultural values embraced by those overly empowered by excessive copyright protection. And these things can be changed by society, if we will it. They're not universal constants.

I care even if the status of creators is undetermined. I wish all your media is thusly edited, please never leave your bubble