Its not strictly about money, but simply put, if the store isn't at least making breakeven in some way-functional advertising, more sales, direct rents, etc.- on the space being used for gaming, they have to change something or there will be a big hole in their revenues.
In another thread that covered this topic, I pointed out that some stores offer "free" space and subsidize this by having (slightly) higher prices on everything else in the store. Several responded they would stop shopping at a place they noticed doing this.
The fact remains- a store can only support so much space that does not contribute meaningfully to its bottom line being healthy. Game space in a retail store HAS to be paid for, the only question is by whom- the gamers using it, the other customers, or does it come out of profit?