Your evidence that "no one uses X" is point number two. It is support for your first claim, which should be upfront. And the fact that you have a list of damned good reasons why no one uses X should help them get on board with your point - that is, after you've made that point, they should be thinking "Yeah, I can see why no one would use X." Then you present the evidence that no one uses X.

And if you don't have a list of damned good reasons why no one uses X, then they shouldn't give you any money.