you say thats just good business, but thats not always the reason. It would be good business for BT not to give access to they're fibre network to other companies but they are forced too. Also is it not good business to sell these channels to virgin for a large amount of money up front instead of trying to gain a few £30 customers here and there.
Virgin sold their TV channels to sky a few years ago, may be they should have kept them. It would have been a good bargaining chip.