“FBoy Island” isn’t totally unaware of how bonkers it is, as evidenced by Glaser’s pointed jokes about the cast’s macho nonsense and the fact that eliminated “f-boys” get exiled to a beach shack labeled “Limbro.” But it also never quite interrogates its own premise enough for it to make much sense, either. ... Every episode brings a new set of arbitrary rules and allowances for when the contestants don’t feel like adhering to them; by the fifth episode, practically the entire premise crumbles in front of our very eyes.