Yul, Ozzy, Becky & Sundra didn't need Jonathan to get rid of Parvati and Adam. They got along better with P/A because they were all closer to the same age. Jonathan was closer to the age of their fathers and probably acted more like their father than an equal. He had a tendency to be bossy. He came across as smug and abraisive. Sure he was a good provider and they did eat very well while he was there but face it, there's only a few days left in the game. They all ate well thanks to the picnic and leftovers, they bonded without any friction while Jonathan was at Exile Island. He had served his purpose, they couldn't see any use for him in the future (4 Aitu - 2 Raro), it was an opportunity to possibly win votes (for Yul since he is seen as the leader) and basically it got rid of negative energy. Nobody trusted Jonathan. The 6 remaining know where they stand with each other (or at least think they do). It really made sense for Yul to get rid of Jonathan but it was hard to read his vote last night and I would have sworn it looked like he had written Adam.