Do you think they're trying to target their CPC advertising to the "real" (college students, etc..) users of Facebook? I logged in to see some of they flyers they're advertising, and they really are cracking down quick with affiliates. The other day I went in, and it was saturated with affiliate offers, so many "work-at-home" type stuff.
I went in right now to check what flyers are being advertised, and I'm seeing, cars for sale, and apartments, rooms, etc... for rent, another flyer I saw is from a company looking for an intern, and all the flyers look like they're from the "real" users of Facebook. That's why everybody is getting crazy conversions due to the target audience, and this is probably the reason they don't want affiliates.
I can see where they could get this idea from, since they do call this advertising, "flyers". I haven't gone to college, but I'm guessing these flyers are like a bulletin board where students have stuff for sale, they make a flyer and post it on a bulletin board.
It also explains why they have a limited daily budget up to $50, and how they don't have advanced stuff with their CPC program, for example: their keyword option is limited, they don't tell you how many clicks you'll get per month for your campaign or "flyer". They left all this stuff out since they don't want affiliates in there and want to keep it strictly for the "real" Facebook users.
This is the only thing I can think of since they're banning everybody left and right.