Never attribute to malice that which can easily be explained by stupidity or laziness.
In a system where who you know is as important/more important than what you do, it's possible the stupid does rise in the ranks. It's not the complete moron level of stupid, but the type of stupid who does have the smarts to fool other people into thinking he's competent. Hell, Roger Goodell himself fits into this category. Happens in other C-suite arenas too.
Most mistakes are made due to laziness and apathy. Even the smartest people will make mistakes if they don't put the effort in when it's something they don't care about. Justice Chin's questions just reeked pure laziness and nothing more. Was he actually pissed that this case got to him, as opposed to the other 3 federal judges who showed actual interest even if they thought it was silly for it to be in court? Certainly possible - pissed that he had to deal with it so he didn't do his homework like he does for his other cases. Who knows?
As for Justice Parker? What's interesting is that he himself (in the oral arguments) actually said that the normal standard of deference given to arbitrators doesn't necessarily hold when the arbitrator isn't a neutral party. He clearly spent the time on the case. So why did he rule the way he did? I suspect ultimately it's because as a generally pro-business guy, he thinks the NFLPA knew or should have known what they were getting themselves into with Goodell as arbitrator, and doesn't feel the need to protect powerful unions from making stupid decisions, and that the union therefore needs to show real strong evidence of bias which he didn't think they did.