Who is he 
The guy responsible for giving bitcoin its worth. Without him, we'd be trading in double digits now.
How do you get to that? He is actually the opposite of what you saying.... without him we would have been trading in quadruple digits by now. The amount of damage Mt Gox caused the reputation of Bitcoin,
Surely it was the only game in town for many years. Maybe somewhere else would've opened up but there wouldn't have been any type of economy without it. If only he'd shut down when he was still ahead.