The answer to the optimism and to the question of what he gets out of it is pretty obvious: Neil Burns craves attention. As Oscar Wilde wrote, "The only thing worse that being talked about is not being talked about." That is, some people fear obscurity far more than they do being wrong. It's long been a truism that there's no such thing as bad publicity, which may explain why even the most pointed criticism of his work ends up stroking his ego. It's not about being right. I really think he doesn't care whether anyone believes his story about being a physics student or playing golf with Armstrong.
It's not about the money; that's why he gives the book away free to anyone who asks. And why, early in the book, he advises the reader to give the book away if he doesn't accept the supernatural premise. He just wants his little booklets out there. He's willing to pay to be a Person of Note, even if it means being the court jester. Sadly none of his literature that I've read stands on its merits, being insufferably narcissistic, poorly paced, disjointed, one-dimensional, and almost entirely lacking in charm, rhythm, texture, or color. So he's got to take the publicity he gets. If people are criticizing it, he theorizes they must be reading it.
If he would stick to historical figures that few people care about, and avoid making allegations of fact, and find a good editor, he actually might develop a following. His problem here comes only when he makes allegations of fact he can't support, and when he drafts recently-deceased figures (who have, as has been noted, close living relatives and still-vibrant professional reputations) to play parts in his ghost fiction.
I'm satisfied if he never comes back. I reviewed his book as promised. And his record here already amply shows that for the purposes of ascertaining truth and evidence he is largely unwilling to participate. That should tell most rational readers how credible is allegations of fact are. If he does come back, he will naturally enjoy the lively participation he has witnessed from his critics.