Earlier quoted context omitted.
In my experience, judges will themselves excuse jurors who have family in law enforcement (parent, spouse, sibling), which means the lawyers don't have to bother using a challenge on it. I would expect the same will happen with many/most criminal convictions, especially when they are related to the crime that is alleged. That's not been my experience, and I've sat through the process in San Francisco 3-4 times so far…
At least you are judged by a jury of your peers. Of course by "your peers" we mean we exclude people with the same profession as you, and we don't really mean people of the same social class. It might be people from your general area, unless the trial happens somewhere else where the laws favor the accusing party. But at least we can guarantee that your peers are humans. That ought to be enough. Best system.
You're not though. The one trial I was one was a murder case and the two defendants didn't speak a lick of English. All of the Spanish speakers were weeded out because English is the law of the land and you are not allowed your own interpretations. Do you really think that is a jury of their peers? I owned up to speaking a few words of Spanish and vowed to use the official legal translations only, and out of desperation I wasn't excused.
When the police interrogated one of them we weren't allowed to translate the police interpretation both because we weren't official translators and because the policeman's words were not evidence. The official translation didn't match what I think the cop said. I followed the letter of the law. I asked the judge if we could consider the video of the interrogation and the judge answered in the negative. Eventually we convicted a man of second degree murder. The judge even sent out thank you letters. It's definitely up there as one of the most revolting things I've done with my life.
That ought to be enough.
It's not. Even if you ignore the baked in corruption it's an awful system designed by people enamored with a bullshit concept of legal precision.
There are plenty of things that could be done to improve it, but aren't. So here we are. Allowing felons to sit on a jury probably makes someone feel good but does little, if anything, to address the problems with our legal system.