I'm not too surprised by the result - at the beginning of any new business, all you really have are the initial people on board and the quality of their abilities. What's going on now matters less than the ability of the founders to react and shift as needed.

For the tl;dr crowd, what mattered most to investors is the quality of the founding team. The paper finds that operational abilities and expertise of the founders is important. Relevant paragraph:

"Given the importance of team information, what is the channel through which human capital information is important for early stage investors? One explanation is that the operational or technical capabilities of the founding team raise the chance of success, especially in the earlier stages of a firm’s lifecycle, when experimentation is important. An alternative explanation is that high quality teams have attractive outside options, and can therefore credibly signal the quality of the idea. We find evidence that human capital is important at least in part due to the operational capabilities and expertise of the founders."