I don't. I could argue that no two penalties are precisely the same, small sample size, etc. But the point of not being obsessed about referees is that I'm not going to put in remotely the same effort (as some clearly do point out their flaws and alleged biases) to counter the idea that they're all out to get us, because it's pointless, unresolvable and dull.
We just beat United 4-2 in our best performance for months, and we've had ~15 pages about referees being biased against Liverpool. Someone came into the thread late, having not seen the game, to talk about it and has been virtually ignored. Even if I *did* think referees were consciously biased against us, it would still be a pointless conversation. I have no idea when it became more interesting, to some, than discussing what was actually a good game of football.
Of course, there's only been 15 pages of referee discussion because people, including yourself, have come out with all the conspiracy theorists clap trap.
Here's the bald truth which we all have to come to terms with: football fans will always blame refs and always claim refs are biased against them and always claim that various people/groups are out to get us and do us down. It's an inexcapable part of fan culture; in fact if you want to get all socio-psychological about it then it's a form of ritual to reinforce group identity and shared bonds; them against us and all that. It will never go away. And as I've tried to point out that doesn't mean that they are always wrong; it's occasionally possible that accusations of bias are true.
But in reality, as you say, it's not a particularly interesting discussion and it's best left as background noise, or slightly queasy wallpaper. Most of the time when I go through post match threads my eyes just slide over the referee posts. They are expected, almost comforting in their ever-presence, but not anything to engage with.
It's when people trapise in with wagging fingers like schoolteachers trying to tell people how wrong they are to suggest referee legerdemain and how doing so makes them conspiracy loons etc that it all starts getting out of hand and taking up space.
Just leave it be. Who cares if it's 'unbecoming'? or if someone might take the piss? If they're football fans they'll almost certainly say the same things about their own club and referees.
I'd much rather read blah blah about biased referees every few posts then some of the shitehawk stuff said about our own players and occasionally manager. Now that does need to be challenged and verbally headbutted. Relentlessly and remorselessly.