Would the other elven people have stayed in Valinor if the Noldor hadn't left when they did? Imagine Feanor staying with all that hate and anger and resentment staying in a realm that's meant to be the perfect place to live in. How long will it be before he drove the other elven people away to sail to Middle Earth? In fact, how long will it have before he's banished again and sent to Middle Earth as a punishment because he's causing too much trouble? As a writer and studier of human behaviour because of said writing, I think it was ultimately always destined for the elves, whether be just the Noldor or a mixture of many others, because of Feanor's attitude. He is a person that people wouldn't like to be around because of his attitude towards the Vala that would have grown to being extreme if he had stayed in Valinor, (and I do think the Vala aren't as great as the other eleven people think they are, other than Ulmo who saw the darkness Melkor had.) When it comes to it, elves were always going to return to Middle Earth because of Feanor as a person. He could Have stayed and been sent back as a result of being rebanished, and since he's a charmer, I think he would have drawn more elves to his ideas and go with him to Middle Earth, seeing the Vala being unjust. Feanor would have still been wrong in many ways, but so would others. Feanor and Galadriel are also my two favourite elves.