Why couldn't people act in 1956?

I know I can't expect old movies to be technically sophisticated---but I don't understand why acting and writing in old movies is always so laughably bad. Even in well-received movies, like this one. Jesus Christ---Dorothy Malone was handed an AWARD for her acting in this movie! How did Oscar voters distinguish between "good" and "bad" performances in the 30s, 40s and 50s? I'm not being facetious. This isn't a rhetorical question. Did they just assign winners randomly, like by pulling names out of a hat?

Before you start telling me about how filmmakers like Sirk were geniuses, and how their stylized use of color and light were brilliant, and how they were making all kinds of ironic commentary, can I ask: instead of concentrating so hard on making everything as fake as possible so he could delight in deconstructing it's fakeness, why didn't he instead concentrate on just telling good stories? And maybe have his actors deliver lines in a way that reasonably replicated actual human speech patterns? And why didn't other writers and directors of this era do the same thing? Shouldn't acting and writing be timeless arts? How come nobody in 1956 knew how to act?

I seriously doubt movie audiences in the 1950s, on the whole, were sophisticated enough to appreciate Sirk's use of irony. I'm sure they just took everything at face value. I mean, people of my grandparents' generation would laugh out loud at people like Danny Kaye and Red Skelton. Seriously. I mean actually laugh out loud. So I'm sure when they saw movies like "Written on the Wind", they would gasp when someone got slapped across the face, or when a word like "miscarriage" was uttered and dramatic music underscored it. So what's the deal---were these directors just thinking, "Some day, fifty years from now, when acting is realistic and moviegoers are a little smarter, I'll finally be appreciated for the genius that I am!"

Is that what we're supposed to believe? Or do you a think a time will come when movie fans---or even serious film critics---will stop romanticizing everything about the "golden age" of cinema, and finally identify these movies (or most of them, anyway) for what they are. Poorly written and laughably acted.