Anecdotally, regarding raising private funds. When I've talked to people with money, they would rather fund established research on what they perceive as a "legitimate" disease. Think cancer, Parkinson's and AIDS, certainly not ME/CFS. The idea of throwing their money at what they perceive as a "junk" medical diagnosis with few researchers and small unreplicated studies seems risky and foolish to them. When they learn the NIH doesn't consider ME/CFS important enough to fund much, it just reinforces that opinion.