I know that there are some stories about bad experiences in the fulfillment centers, but keep in mind that those positions are temporary seasonal work by unskilled labor.
The tone of your writing suggests that you are OK with treating these people badly. If a company treats some set of its workers badly, what stops them from treating other employees the same way? In this case, they may treat SW engineers well because there is a lot of demand for engineers, and they have to be treated well to retain good folks. That is not comparable to the good culture that OP claims WF has.