Sorry to interject, but thought I'd share an opinion.
First, what is your motivation to troll somebody's history of posting, back to 2008 ? Are you paid to do this, or are you so bored, you have nothing better to do ? Why did you stop at 2008 ?
My guess is the reason the person didn't write on this forum, is the same reason Bill Clinton hasn't written on here. Or Lady Gaga. Or my neighbor Fred Jones.
You seem to suggest an obligation to who you are writing to, as if they have some obligation to write on this forum. All they did was post a Youtube link to a very interesting and useful doctor's short discussion !