From a business perspective maybe but i'm assuming you don't make a penny from any FPS's sales , more FPS's will generaly mean the standard has to be set higher every time a new one is released otherwise the game will face abysmal sales Haze to cite an example.
We have more choice , we're not overwhemed by the choices of FPS's , I've never heard of any one complaing about there being too many products for them to choose between , choice for the consumer is always a good thing.