You dont potentially take ev directly away from another player when you sell half your action after satty qualification though. And this would be extremely hard to control whereas preventing the rail from helping out one player in deal discussions is actually a possibility (although a poor one imo). I dont really like how these insurance deals come about and I'm not sure saying its just business is an adequate response when someone is getting screwed because of their lack of financial connections.
how do you directly take ev away from another player (apart from less financial pressure on you - the same as selling pieces pre tourney albeit on a smaller scale)? No one is getting screwed, the tourney is still being played out with the advertised payout structure. Your choosing to do business with someone offering to do insurance over doing business with the other player because its a better deal for you.
*unfairly take EV