Of course no one should believe an explanation until there is very clear evidence to support it, and even then, the explanation is subject to constant revision as the quality and quantity of information improves.
But where do self-appointed policemen like this jerk Jay Melosh come from? Someone else has put forward an hypothesis that is as yet unproven. So, somehow this Jay Melosh is supposed to be famous because he "debunked" it, but asking the obvious, "where is your evidence"
I have a suggestion for Dr. Melosh. It is an interesting and creative hypothesis. Instead of sitting on his vestigial tail carping at the ideas of others why doesn't he find something useful to do, like see if there is evidence for or against it, or go and find his own problem to work on.
The hypothesis will likely turn out to be wrong, likely on the grounds that most scientific hypotheses turn out to be wrong. But, in the process of collecting evidence you learn a lot of facts and might in addition to finding that this was wrong, find something else that was right, none of which will happen if you sit on your tenured chair and preen your tenured tail feathers.
Of course it is unproven, but I think rather less than more of this Dr Melosh for pointing out the obvious.
When allegedly educated people can't use language properly, the slippery slope of dumbification just gets steeper. Sooner rather than later we'll all end up in a jumbled heap at the bottom of it.