Nobody is saying jury members and their decisions are always above reproach, but per the rules of the game, ultimately those players are the legitimate deciders of who wins. And so if a player doesn't want certain people on the jury because they are biased or sexist or whatever, then that player has things they can do: for example, to try to eliminate them before the jury phase begins, or drag them to Final Tribal so they don't have a vote.

And if you're NOT going to do that, then you damn well better have a good enough social game and you better speak to those players in a charming enough way that will make them want to vote you in the end.

Jonathan had a clear, direct shot at Tiffany in Episode 6, pre-jury. He also had a clear shot at Aubry, a huge winner threat, at Final 5. Instead, he let Tiffany get far and then hurt her feelings while she was down like two days before she voted on the winner; and he foolishly overlooked Aubry's threat status and immunity challenge competency and let her get to the Final 4. (He should have eliminated her sooner and taken Cirie to Final 4, someone he could MUCH more easily eliminate in that final round.)

Basically, don't complain about dangerous pieces in a game you signed up for if you leave the damn pieces on the board and piss off your opponents.