Specifically, the gates foundation does not fund interventions or research into health conditions in western countries. To make a case, you have to suggest that research on CFS (particularly epidemiology) is sorely neglected in developing countries. Otherwise the Gates foundation will explicitly ignore such requests.
That's true, too, that it's present there and neglected there.
However, I thought they did include domestic research for populations considered disadvantaged, which would basically include patients of nearly any disease which affects more women than men. (not counting breast cancer, which I think has caught up to everything else, via advocacy).
Though we're at the bottom even of this list. Someone (you?) made a chart showing ME/CFS is the worst underfunded (of diseases in general) by far, and migraines pretty bad also. Not sure you included fibro and IBS but they are not tons better than us, though they get about 2-3x the funding (US-NIH).
Don't they have women, children, and minorities on their list, even in Western countries?