First off, I love sports and love rooting for my favorite team or player in all sports, but I never blindly root for anyone.
Example, it's 4th and 3 my teams offense is just inside the kickers FG range and everyone knows it. Then just before the snap blocker on the end just jumps and produces a false start thereby moving the line of scrimmage back 5yds. The next play the kicker misses the attempted FG short by 2ft. Now in this instance I know that my team screwed the pooch as it were. But to some who will blindly root, this was an officiating problem, he was drawn offside (even though he clearly wasn't), or some other nonsensical reason as to not make it not the fault of the player/team.
This is just one of many examples I could think of, and what I'm trying to say is that when all is said and done no excuse can make up for a bad play. When people try to argue that this is better than that, but do so out of blind fanaticism not accounting for something that can be proven better, this makes no sense to me.
I do believe you should love and root for your teams and players, but do as an informed fan not just an idiot that likes the color of the jersey they wear. This way when someone is disrespecting your team or player, make an informed argument backed by fact. Don't come back with some lame response like "Yeah well you're a moron!" This just makes your stance just that much worse and you're not going to change the opinion of the person talking stuff about your team. In fact more often then not it will make them steadfast in their opinion that your team is crap.
So if you're going to be a fan try to be an informed one, and if you can't be informed don't say anything. Enjoy rooting for your team or player and just leave it at that. If you don't and someone puts up hard facts to discount your belief then you'd better be able to counter in the same fashion. Or you'll just be another bandwagon jumper.
Because when it all boils down, stats don't lie.