I'm guessing that many of the people who participate in these communities have a significant number of bitcoins to their names. Given the current trading price of BTCs many of them are probably virtual millionaires. All that could go poof if the coin were to collapse. Not really surprising that they would be very passionate about these issues.
That may be part of it, but if it were purely about wealth they could surely just sell some of those holdings right now and become actual millionaires.
