It actually takes effort to port a game to a different system or OS. I'm not a fan of exclusives either, but at least sometimes there is a real reason (we did not code the PS4/PC/Mac/Linux/Wii/PowerPC/32bit version), but this is an entirely artificial and arbitrary restriction.
Edit: technical reasons aside, I guess there is no difference. But at least one excuse can fall back on semi-technical reasons... This sort of exclusivity is purely for marketing and contractual reasons. It actually requires more effort to make the game exclusive than it does to make it multi "platform".