This is a great point, and really meshes with my experience as well. We've had some great salespeople but deficiencies in the product (mainly lack of certain enterprisey features) made it very hard to sell. They worked their asses off and closed almost no deals. And our product was good and really close to what the market wanted. Contrast that with most startups which not only have to convince you to open your wallet but also to do so for a solution to a problem you don't currently have (or at least, don't know you have).

If you have an excellent sense for products then the model might work, but I've seen some of the smartest people I've ever met walk right into a wall, even when doing everything they can to reach/verify the fit. It's an incredibly hard problem