Humans by nature, not just refs are biased and emotional and make mistakes.
With that said I can see bad calls intentionally made on the field when players insult the refs ect. We don't hear what's said on the field and that's a good thing. Refs have favorite teams and dislike others just like we do. I used to get PO'd about bad calls long before we had reviewable calls. We also have many more rules now, horse collar ect. To me that one can simply be called unneccessary roughness but whatever.
Bottom line is complaining about bad call changes nothing. Yes we all hate to see them but it's part of life in every sport.
OK now to the bad news. I too have noticed less football discussion especially about the NFL. I must admit I'm not here as much as I used to be but not by choice.