Did you read the whole thing? There's an entire section at the end that talks about what current players are doing wrong, while raising the question of whether even the suggested approach is fundable.
That section is very short and very general when compared to the rest of the very detailed analysis. I know a tiny bit about the failure of cargolifter and their problem wasn't just funding and market fit. They also had a big list of technical issues, not least with making the damn thing at least somewhat all-weather (still nothing compared to jet planes).