Basically, Sony and Nintendo get away with say that they don't buy exclusives because they call them development partnerships etc. Sony will offer development capital for large projects (which are the most risky as far as profitability); like lending support staff, free dev kits, use of facilities, or giving out internal "development tools" for games Final Fantasy, Metal Gear, Unreal Engine, etc. or they can waive licensing fees. Nintendo did it with RE4 and with any takers for Wii launch (Red Steel). There are lot's of different ways a manufacture can do this.
It's a very flexible way of attracting exclusives, with out investing a lot of capital for the manufacturer while reducing the risk for third parties.
I would cite regulation, but I know you will simply ignore it.
