You were dismissive of opinions that contradicted your own when you said "it was a terrible decision, nothing more, nothing less" (paraphrased). I think that's what set people against you.
FWIW, it wasn't the most blatant red card ever seen, and could quite easily have been awarded a yellow card. But the referee thought it was a red, and the VAR didn't strongly disagree with him. People who also agree with the original decision are entitled to do so, and that doesn't imply their bias.
Other opinions about other teams not having similar red cards rescinded are also worthy of discussion, as is the perceived influence of Sky and other media.