Steam didn't have to apologize. I remember this all going down although didn't get too invested into it because it didn't apply to me. And after doing further research I can find no connection to steam at all. Where did you find this information, I would love to know the source. This was all on FROM. DS3 doesn't have anything to do with Steams own VAC. I'm not calling you a liar I just would like a source because something does not add up here.
As for the other examples there is gems like
"The only rule he broke was gifting games for cash, but Steam didn’t know he was doing that and confirmed to him that wasn’t the reason for the ban." - He was pushing the boundries anyways. Just because they didn't communicate the reason for the ban doesn't mean they had no reason. I don't feel bad for the guy at all. He was already breaking rules, what else was he up to?
The second one is just a VAC ban. He can still use his account to purchase games and play games with the side effect of not being able to to play online on that account with steams "gold" titles (tf2, CS, HL). Chances are he was up to no good.
The third one is a steam community ban. He was just banned for talking about a topic you a arnt supposed to talk about. All he is banned from is posting in the steam forums for that particular game. NBD. This one is exhaustingly talked about in the rules (whether you support it or not).
Only one of these cases a steam library was taken away. And he admitted he was up to no good just that steam wouldn't tell him why in particular he was banned.
I feel like you are grasping at straws to make a point. I do acknowledge that steam bans happen and you could lose all your games. But these do no good to enforce your point... almost seems like fear mongering.