Just because the HGP turned out to be worthwhile doesn't mean funding it in the right place was the correct decision. If the expected value of the HGP was below the opportunity cost it should not have been funded. That the actual value turned out to be higher than the opportunity cost is irrelevant.

To say it another way, I think that playing the lotto with the goal of earning money is a mistake. The fact that some people win it and in fact make money doesn't change the fact that they were wrong to play it in the first place if their goal was net gain of money.

That said I have no idea what the expected value of the HGP was so I have no idea whether it was a good decision. I just want to chime in in support of thinking about the probabilities involved in the right way.