The plot is propelled not just by characters being stupid, but by them REPEATEDLY making the same mistakes over and over. Seriously, how many times does a prisoner have to beat up guards before you RESTRAIN the prisoner? 5 times? 6?
Also if you were stranded on a desserted island with a dozen other attractive 20 somethings, and all of you had amnesia, wouldn't someone say, "Huh, it's weird that we're all attractive and about the same age." That's just poor casting not supporting the (bad) script.
Just awful; don't even waste 30 minutes on this show.