Why do so many people act like old movies are the best?

Everyone acts like old black and white movies are infinitely better than today’s movies. When I watch them I think that in many cases the cinematography is cheesy and the dialogue is forced and overacted. Whereas today I believe acting has reached it’s artistic peak without all the over-exaggerated characters and fake dialogue. So why do people feel this way? Does it actually have to do with the way the movies were made or is it nostalgia?