We'd definitely be dead. Korea of this time period had very strict class system. I actually find it very interesting and admirable that the ML was able to reach his station.
As for the MC it is totally possible that his family was either doing something wrong deliberately or just too powerful during a tumultuous time. It doesn't make it right but Emperors did this to Nobel families time to time when they grew too powerful. Infact the MC should be angry with the Emperor, if it hadn't been ML than it would have been someone else.
Moreover a nobel family like his has likely done all kinds of "problematic stuff" as well. For all we know his father might have led to other people's death and pain the way ML has led to his.
Maybe I've just watched too many Chinese historical dramas or read novels with this kind of setting because I just let the story unfold. Of course I feel for the characters but I try to see it for what it is rather than what I want it to be.
Half of these readers won't be able to watch shows like The Story of Minglan (highly recommend the show if you like historical settings. It has low melodrama, interesting and varied female characters and sympathetic but complicated MC and ML, one of the few historical pieces that feel realistic).
I keep reminding myself that the seme isn’t just a “villain” he’s a complex character. He’s mentioned how when he was younger he was thrown into the battlefield in a “kill or be killed”, “fight to the top” sort of situation where he works to weed out corruption on his own terms. But he needs power and influence (fear) behind him to enact change. I have no doubt once the story progresses we’ll see how the ukes family was either framed (seme may have had no knowledge or part in this) or rightfully caught up in something bad but obviously from the perspective of someone whose family was killed regardless of if they committed a treasonous or illegal act you’d look at the executioner as the enemy. But there’s always two sides to every story and the uke is what we call an unreliable narrator. This is all excluding the uke and semes personalities which I find slightly abysmal on both parts but we’re starting to see character development. This story is so slow going it feels like it hasn’t truly begun unraveling yet.