I'd agree, but if we're trading tropes, the absence of evidence is not evidence of absence either. He's easy to discredit and dismiss, and it's meaningless to my life whether he's real or not, but if you've got billions on the line in the space propulsion game, I'd think you'd need to have gone deep into his claims to determine he's full of it.
This is your answer.
Extraordinary claims require extraordinary proof, and Lazar can't ever seem to manage the latter.