I disagree with your interpretation. I think Justin is saying,
"If the fundamentals of your business are good, believe in the data even when investors don't recognize its value. Eventually, they will."
But what about respecting the Principle of Charity [0]? Once we do, then we shouldn't we also apply the Precautionary Principle [1]? We find that, if we do, then what the OP prescribes (lead, not silver, bullets) is hardly worth questioning, since otherwise we are claiming there are hidden risks of hard work (which, to be fair, do exist; burnout et. al are not pleasant to deal with in reality). I think that we can agree this (that we should not strive to work hard, especially after rejection) is harder to accept.
I paraphrase, but Poe's Law is in full effect here.