Why is "maximalism" even bad by itself?
Because I think at least in some cases he is clearly reasoning backwards from his desired conclusion to whatever evidence he can make use of from his vast research, specious or not.
Are you sure yo're not reflexively bouncing into center?
A fair enough question, aside from the fact that the "center" here is still supporting that Stalin did tremendous good for the world and that countless accusations made against him are ludicrously false and many others are overblown.
It is certainly true that I am very wary of absolutes (in the sense of something having entirely X quality and never the opposite quality), because I like deductive reasoning but it makes me acutely aware that things that are frequently presented as absolutes aren't and deduction is constantly misapplied. I guess you could also word my criticism of Furr as that he seems to use motivated reasoning to defend a very absolutist view of Stalin. This doesn't mean he doesn't ever make good contributions, and very often the criticism he receives from liberal historians and other commenters is frivolous (I've read some of his responses and he often does a good job of refuting them), but at base I struggle to have confidence in him because of some of his sillier arguments.