Commenter's aim is to seek knowledge. He is putting forth a hypothesis, and is seeking alternative theories. If he gets viable ones, he'll put less faith in his hypothesis, or may abandon it altogether.
If one merely finds flaws in his hypothesis, he'll realize he's wrong, but will be no closer to the truth.
Pointing out that he hasn't backed up his theory is reasonable, but it doesn't bring him closer to his goal.
A relevant quote from Carl Sagan:
"If you’re only skeptical, then no new ideas make it through to you. You never learn anything. You become a crotchety misanthrope convinced that nonsense is ruling the world. (There is, of course, much data to support you.) Since major discoveries at the borderlines of science are rare, experience will tend to confirm your grumpiness. But every now and then a new idea turns out to be on the mark, valid and wonderful. If you’re too resolutely and uncompromisingly skeptical, you’re going to miss (or resent) the transforming discoveries in science, and either way you will be obstructing understanding and progress. Mere skepticism is not enough."
He also gave some good examples from the history of science of theories that eventually turned out to be true, but were originally on shaky (or even faulty) grounds for a long period of time. A culture of skepticism would likely have killed those theories. Unfortunately, I noted only this quote and not the examples.