Money is the biggest motivator. Not many players have or care about their dreams. If they get a fat check they forget about their dreams or whatever ideals they have. It's true that money is not the only factor but that's overstated. If you have 3 offers and 2 of them are extravagantly more significant you will ignore the 3rd one even if it's the preferred situation, destination or better fit for the player and he will consider only the other two
Just an example. You have a player who has offers from Inter, Arsenal and Chelsea and for some stupid reason none of us make CL. And he's an AM. At Inter, he'll definitely be the starting playmaker, he prefers to move there because of x reasons (likes the city, the coach, the teammates, the history, the fans, the league, whatever) but Inter's offer is let's say 2,5m net. The offers from Chelsea and Arsenal are both over 4m net. He will either ask Inter to increase their offer to at least 3,5m net or he will just say no. Then he will weigh his options between a 4m and a 4,2m offer. That 200k is not enough to sway anyone at this level really, but the 1,5m difference is. Hence, the player would have rejected Inter for the money but he wouldn't reject Arsenal or Chelsea just for the money. He'd consider both for the money but he'd reject the one that's least appealing even if their offer is a bit better than the other's.