Well, in the first season, the Navy Seal (Rudy) was never voted off as such, he was one of the last three contestants and he lost an immunity challenge. By that time it was pretty much everyone was trying to outmaneuver the other two.

The ex-USAF survival instructor, who is apparently the only contestant ever on the show to get a fire started, was the first person voted off, not because she was a liability, but because she was a threat. (Prior to that, everyone who was voted off was "the weakest link", to plagiarise another show.)

But I never bothered watching the last couple of episodes of the first season, and I've never watched any of the subsequent seasons.

If you're going to watch it, then you should simply accept that it's not about survival as we discuss it here; it's about tribal politics. If that turns your crank, fine; if not, don't watch it.

(It was apparent from the first few episodes that many of the season one contestants had read up on survival skills - they knew, at least in theory, how a fire plough worked, for example - but had no idea of how difficult it was to do in real life without having practised it.)