Why?
Bigger bubble, bigger pop.
How do you figure it's bigger? In percentage terms or absolute? In percentage terms the 2011 bubble was bigger and more abrupt. In absolute terms we've already popped way farther than in 2011 (but absolute price should be irrelevant anyway).
Hype, media, volume, percentage and absolute price.
It's only smaller percentage wise if you start the 2011 bubble at like 0.50. IMO, the bubble started much later. The log chart only gives you a small part of the picture of the Bitcoin economy during 2011.