Holy crap, I never noticed that!
That does seem odd
You'd think eating raw mole rat meat would give you a bad case of worms or something, but nope, just radiation.
Well, at least they (sort of) fixed it in FNV, with raw meat giving you a strength penalty.
Ok, to be fair, it is a game and as such some departures from reality are to be expected. Like the fact that you can't go to the bathroom. And besides, there was no sickness in FO1 and 2 iirc.
Anyway since I haven't done one in a while:
630: Apparently, radiation is also great at preserving corpses, because not a single body decomposes in the game. No, really, they just stay there in perfect condition. They could have despawned, but I have yet to see it happen.
631: Judging by how the bodies in raider camps never seem to decay, it is safe to assume that the raiders of the future are all expert taxidermists, with a very morbid sense of humor.