I respect where you're coming from Ugs, but I have been in this situtaion in the world of work multiple times and it almost never works out. In the non-sporting world contracts actually hold water and there is usually something called a non-compete clause. I left a job for greener pastures and a much improved compensation package, but my former employer enforced my non-compete and sued both myself and my new employer for tortious interference. Needless to say -- I got the boot. Found myself not getting paid by anyone. Had to get into a slightly different line of work.
If a player has a contract, and another club makes an offer fine. When the offer becomes agreeable to all parties involved -- good. Happy Trails to you, sir. You have earned yourself a nice payday. But to holdout when you have agreed to provide a service and are being paid handsomely to do so whether you play or not -- totally unacceptable! So he wants to play for a "bigger" club and make more money, now that he has become aware that the possibility genuinely exists. Alright, who can blame him? But you continue to do your job in the meantime! Anything else is just being a d**k.