To anyone who still is pissed off at how the hero is acting... imagine yourself as the main character of a 90s harem anime, like Tenchi Muyo or Love Hina. You know, where the most tropey cliches happen that cause the girls to mistreat and beat the shit out of the MC when most of the time it was a misunderstanding or accident.
In the previous run he put up with all of that shit for 10 years, getting the snot beaten out of him by people who were supposed to be his allies and didn't seem to show him any kindness (yes it's his word against there's) but so far Silvia acted like the careless tunnel visioned meat head who didn't show him a shred of gratefulness despite him bidding for her, letting her join his party and not treating her as a slave.
And yes, slavery is bad m'kay, but just like you don't know Silvia's backstory, you don't know the slave trader's backstory either, but the direct parallel is obvious. It's their jobs to take care of their customers and they do so, they even handed over the elf slave to MC without taking money so they're holding up their contract at the very least and they can't save all the slaves because they're encumbered.
Compared to Silvia, who sacrificed all her allies lives, twice now, the first time she lost and became a slave herself (and any other elf who survived), giving them a horrible fate. The second time around they all for sure died and she didn't give a flying fuck about anyone, even willing to collapse everything and murder everyone, even any slaves that didn't get killed in the first volley of arrows.
If Silvia was labeled as a villain and we weren't dealing with slavery (m'kay), Silvia would be labeled as an out and out villain, if at the very least a terrible anti-hero due to her selfish pigheadedness and blind self righteousness (that doesn't even seem to change in the first run despite 10 years with the hero).
So yeah, the MC certainly isn't acting as a righteous hero in most senses (though come on with the goddess, two A's and a D and an F should've averages to a C, that's technically a pass so you should've just let him go home but just wiped his memory and shit) but I agree with this mentality of FUCK EVERYTHING, especially if it's going to be a never ending groundhog day bullshit with terrible people you're trying to be forced to side with or you die.