I used to be a huge turd for years thinking “these plebians liking will Farrell movies are so dumb, it’s a horrible movie with no plot”.
Turns out you can enjoy two different things completely fine in life. I was just being an arrogant fuckwit
Being critical of a film is actually just having a critical opinion about it.
Sharing that opinion with others is something else: a way of deriving personal enjoyment or satisfaction from one’s critical position through sharing it with others.
As with everything else that requires multiple people, somebody deriving their enjoyment of something through others is absolutelly fine if said others are also doing so or at least if don’t really care either way, but not fine if one is negativelly affecting the enjoyment of others to get some enjoyment oneself.
So if you’re critical of something whilst somebody else is not and you “just have to share it with them right then and there”, you’re being selfish and if have even the slightlest shred of consideration for others you should at the very least shut up until after they are done with said enjoyment.
Saying anything other than quick, understandable jokes while watching movies or series is an asshole move.
Afterwards? No, go nuts.
You don’t need my consent to write on a public forum that the movie I just blindly enjoyed is trash from start to end, I may even agree with you - the Star Wars prequels were a personal favorite of mine when I was a youngling.
As with everything, it real boils down to how pushy one is in their criticism.
If somebody who loved the thing goes looking for the opinion of others and finds critical opinions, well, though luck for them - they went looking for it and nobody else posting in what’s a public forum has any moral obligation from refraining to post a negative opinion, IMHO.