I dunno. I agree on the fact that the characters are almost plagiarized but I think they shouldn't be so thin skinned to not accept criticism against their settings and characters.
It's more about the hostility towards these characters and the works they come from.
It's one thing to make an edgy parody of a work, it's a whole other thing to essentially plagiarize 9 characters of 9 different works and paint them as self serving rapists.
The Shield Hero has already tackled and is currently shedding more light into the idea that the reincarnators are assholes who only see the world they stumbled into as their playground, and now they're suffering the consequences for their selective ignorance.
The premise can work, other authors have made it work. The problem here is that the mangaka seems to have a hatred for those characters or the genre as a whole, and when you make your manga based on your hatred of something instead of the passion about the subject you're talking about, it's going to turn people off.
I remember there being an anime about a girl responsible for killing off reincarnator if they proved to be a threat to the world (can't remember the name, only saw a few clips), which tackles exactly this type of issue with the concept as well, yet that one gets a pass. Again, it's not about the criticism of the genre, it's about the hatred the mangaka has shown here.