I imagine the at least some portion of the criticism comes from irritated leftists as well. Harriet Tubman is basically a civ leader chosen to pander to and resonate with a certain US-centric audience, but it should be noted the lack of representation of actual African civilizations as compared to a continent like Europe. Here’s a couple maps to show what I mean:

i.redd.it/6hjvikrkwuu71.png

preview.redd.it/bc6rvax3m4851.png?auto=webp&s=6fb…

It’s inherent imperialism and pandering that the same western countries are given so much love when there are so many really cool civs out there that haven’t been explored at all. Not to mention the fact that the majority of the African civilizations and city states that have made it into the game are centered (unsurprisingly) around the Mediterranean sea.