Except he doesn't struggle. Neither he nor the author ever voice any moral objection. The only problems are 1) he's ugly (by that world's standards); 2) he's naive; 3) in a dog eat dog world, dogs try to eat him (just like everyone else).
But his wife/daughter nearly dying aren't taken as moral retribution. Rembrandt doesn't change his ways at all. He just doesn't have to be as brutal anymore. Yes at one point, Rembrandt and his friend claim to have higher "business ideals" when they were younger... But it was while he was young that Rembrandt engaged in horrendous murder and betrayal -- for which he never voices any regret. So his purported "business ideals" had no actual reality to him.
But Makoto never particularly wants or works towards providing a place for demihumans. The initiative for that lies entirely with Tomoe, Ema, etc. Makoto just goes along with it. Which is the opposite of Rimuru who clearly states that as his goal and works hard to reach that ideal.
?? They're a normal business cartel. And normal procedure of such cartels is remove or at least control competitors. The author never criticizes that. They're "insecure" in the same way that any competitor is "insecure" -- of course someone can come along and hurt you if you let them -- so don't let them. That's what the author perceives as "normal business".
What morally good qualities does Makoto have??
I already argued this.
In later volume, demons casually mention that
they wiped out every last person in a city because 'the survivors can't come back at you for revenge if there are no survivors'. (I'm paraphrasing.) (Also, IDK if those were humans, my impression was that they were different demi-humans.)
You're mistaking the story presenting "messed up nature of the world" with the story "criticizing the messed up nature of the world".
Again, this lack of criticism is more clear in the original work than in the manga or anime.
1. He does struggle as a businessman and he gets wound up in random bullshit here and there. Yes he clears them more easily than it would have been for others but it's not something he'd like to do. Because of Makoto's naivety kid tomoe and orc died, later due to his merchant inexperience Makoto is basically forced into a tough position in Rotsgard and him trusting Rona and getting betrayed and there's more future bullshit to come. These aren't extreme struggles but it's still struggles and events that the protagonist would rather not have and aren't a comedic setpiece but an important reflection of the world Makoto has stepped in. That berates Makoto for still not being used to things around him and not thinking carefully. All of this is a lesson that he learns overtime.
2. Dude it's the consequence of Rembrandt's action it's the most in your face textbook moral retribution for past misdeeds. The only difference is that it doesn't shove that in your face and emphasis the obvious and expects you to pick up on that.
3. What the actual fuck are you talking about did you read the series ? It was initially Tomoe's idea yes but Makoto also sees the place as a precious home where those who aren't liked in the world or are unfortunate can also live in. He literally says that he can't die cuz if he does he doesn't what will happen to the demiplane and it's residents and says that if anyone has to die let it just be him and not anyone else. He has properly taken the role of being Demiplane's ruler seriously after the female Adventurer thing. Because he finally understands how biased this world is. The whole mist gate thing is literally that.
4. They're clearly shown as bad guys who pushed Makoto away and it's framed as a bad thing because it literally pushes Makoto away from the Hyumans side as a whole which is a great loss for hyumans that they've yet to grasp in their ignorance and self centered ness. Dawg do you need everything spelled out to you.
6. What morally good qualities? Dude Makoto's prime reasoning for conducting business aside from (having enough money which was earlier in the story) is just to help people by selling them stuff for cheap, he and his people literally scout wastelands and demihuman areas and offer them to migrate, thier stores sells expensive medicines for cheap for the regular populace, his people go to impoverished areas to provide them high quality stuff for cheap, one of mist town's objective is to also help Adventurers in wasteland. Makoto is described as a person who'll help other doesn't if they need help but because of his experiences with hyumans he's become more biased towards Demihumans and against hyumans.
Makoto does have moral flaws but aside from that he does try to do good things just because they're good. He also saves Lime's orphanage.
7. Wasn't much of an argument.
8. Yeah and? The entire point is the reason demons are like this is because of extreme discrimination and bias of goddess towards hyumans which have made it so they have to rely on brutal methods to ensure their position and safety.
The original work literally brings up multiple of these points and these this are portrayed as something that's negative both Mio and Tomoe say that hyumans foolishness and self centeredness costed them dearly. You think they're not criticised because the story doesn't outright tell you bad shit wrong and expects you to figure that out. The world is twisted because of a force like goddess and Makoto's existence is something that's im opposition to everything the goddess values.