Yeah, it's a good share, and of course I'm not encouraging people to shop at these places, just pointing out that the alternative won't be much better..
I'm not American either, but as you say, the problem is global and local to each country (in different ways, sure, but even in the UK many prisons are now run for profit, so things might not be on the same scale, or as explicit as in the US, but there are similar problems in different variations everywhere you look) which is why representatives within the existing system aren't going to get any significant change either. The whole system is designed to withstand "reform", which is why it needs abolishing, and you can't do that playing by the rules they set, you have to be willing to unlearn a lot and build networks of solidarity and mutual aid and resistance, create alternatives within the local and global community that they can't profit from or control, then go after about 2000 people that are holding the rest of the world hostage, and end this shit.