And on top of that, even when we try to truly be objective in calls that go our way, we often seem to assign less weight to those than the calls that go against our teams.
Which I think greatly contributes to what you say above about too many people complaining their team is uniquely mistreated.
When they are major decisions (i.e., red cards, penalties, egregious offsides on a goal, etc.) that go our teams' way, we often acknowledge but also with an implied "so what" whereas major decisions that go against us is met with very loud yelling/complaining/we were robbed, etc.
Furthermore, and I think perhaps the greater contributor to this are the little decisions, the little mistakes along the way that go our teams' way (yellow cards, foul calls, offsides but no goal was scored, corner or throw in decisions). Those are often glossed over. Maybe they're acknowledged in real time but they're shortly forgotten about after the fact. Whereas, if they go against our team, they stack on top of each other and create this mountain of "bullshit calls" that shows our team was jobbed.