Perhaps even knowing enough to discern between a Mac and PC is enough to make them a poor mark.

Notice that they are saying "Windows support" not "Microsoft Support", not knowing that Windows is a product from Microsoft would suggest they are looking for people with a very low level of knowledge.

I'm guessing retired people who have a good pension coming in.

OTOH that must put an upper limit to the amount people are willing to spend to get their computers back from the scammers. If you only paid $300 for a PC from wallmart you won't pay more than that surely.