Epic's comments shouldn't be taken too literally; they are spin pure and simple.
It goes without saying that Epic could make a Wii port cheaply enough that it could have pitful sales and still be profitable. Epic knows this; they aren't stupid. But Epic has other, bigger things to worry about than the chance to make a few dollars off of a Wii port.
Right now Epic and its engines are very well known and well respect by developers and customers alike. They have tremendous brand power within their niche. But if they started putting out games on the Wii, games with lesser graphics than is expected from Epic, or games with imperfect controls, they could seriously harm their brand. Even one game, if it got enough attention, could drastically change people's perception of Epic - killing their golden goose.
So why might you ask, don't they admit this? Brand power has always been a taboo subject with companys for some reason; few ever admit that they are making decisions for that reason, even though virtually every well known company regularily makes decisions based on protecting their brand. So rather than talk about the real reason, branding, they send out a communicae that will make their hardcore fans feel all warm and fuzzy.
