I don't think you have to watch ALL the games to make such a claim. In the games I've seen, the distribution of bad calls has been uneven. And not just by a little bit.
And I disagree with your middle two sentences, especially when it comes to games where we have no dog in the fight. But even with Rams games, I think all of us here are rational enough to see when the Rams benefited from a bad call, and when they got shafted by a bad call, win or lose. And many have noticed an obvious pattern of the Rams and other teams getting shafted much more than not, while certain other teams get the benefit much more or not.
If you haven't noticed the same pattern, fine. But by your above statement, you can't call your fellow fans who do wrong.