I've watched every single Survivor episode and this was one of my least favorite seasons for various reasons, but what you touch on is what keeps me coming back and what keeps the show interesting for me. Individuals on the jury all have their own unique motivations for voting for/against a winner. Some like the social aspect and will vote for who played the best social game, some will vote for the underdog who made it to the end despite everyone trying to get rid of them, some will specifically vote against the person who blindsided them, etc., etc. I found it funny that it was played up for the jury that Tommy had made final 2 deals with practically everyone post-merge and even Sandra mentioned how awesome that was for Tommy's game. But in previous seasons, this exact strategy has backfired more than once as players started talking to one another and realized they were being two-timed. It's caused people to be voted off numerous times over the years. I made a guess of Dean winning 6-4 prior to the final votes being read, but the more I think about it, the more I"m OK with Tommy being the winner. No doubt Dean played an incredible end-game, but Tommy played a more complete game from day 1 to day 39.
In general, I"m not a fan of returning players coming back in future seasons, but I'd agree that Kellee deserves another shot. And Elaine was probably my favorite player this season, so I'm glad she got $100K from Sia.