I agree with the thrust of the letter, but we need to be a bit clearer with the arguments, since what we are really asking for is not merely more money, but something else.
When we have previously asked for more money, the people at the NIH have retorted, oh we would give out more money, but there aren't enough high quality applications. But we know that this simply isn't true when you have the likes of Ian Lipkin, or the researchers at Stanford who want funding from the NIH, but don't get it. This needs to be explicitly stated when promoting the funding argument - that the best researchers in the world are applying and are being knocked back for studies that would have been funded if they were for another less stigmatised condition.
But the reason why there aren't enough high quality applications is two fold - the first is that there is a dire lack of research capacity in the first place. Lack of progress discourages others from joining the field. The second is that when researchers do apply for funding, they almost always get knocked back anyway - why bother spend lots of time designing experiments, writing applications when you are just going to get knocked back. Much easier for your career if you work in a field where you are twice as likely to get funding.
We need to tell them that the NIH needs to take an active focus to break this catch-22 and build research capacity of a magnitude of order greater than what is currently done.