That graph is dug out whenever the feasibility of fusion is discussed. It's a prediction from 1976 – you should know how credible decade-long predictions on the progress of unproven technologies are.
How does this address the graph? It probably doesn't predict the current situation, but it certainly is consistent with it, that fusion funding is below the "fusion never" line, and look, we have no fusion.
I could be wrong, but the projections are extrapolations based on obviously overly optimistic assumptions about the a) the federal government's desire to fund large, multiyear scientific projects b) the ease of creating an economically scalable fusion reactor