The problem with the one you posted specifically isn't even related to anti-communist bias. Here's one statement that gave it a downgrade:

Capitalism brought with it an unprecedented expansion in social mobility, both upward and downward.

Rating: Mostly False

Also, the llm is rating novel analysis (such as "Marx looked at the differences between kings and capitalists") as false, because there isn't much literature that already discusses things in those terms. So, if you don't want the bazinga bot to give you an F, you aren't allowed to say things in new ways that aren't already established in the literature. What a bright future we have