I'm kind of surprised, Samsung didn't push f2fs more. They initially announced it as a flash oriented and free filesystem, and promised a Windows driver as well. I don't think it ever materialized. And Samsung have enough weight to push it through.
Just speculating. It could be a leverage thing. They created it, and MS gave them free usage of exFAT or anything of the sort (in return for not pushing it further). Could be just usual mismanagement too.