Far from the biggest flaw
Not that the other flaws are technical, necessarily, they're more about policy and design.
Whichever individual or group came up with the crypto scheme and the network, they were clearly very clever. However they also pretty clearly had a simple and idealist view of economics which was doomed from the start.
Having spent some time being told I was 'ignorant to the point of fraud or criminality' by bitcoin aficionados for listing problems I saw with the currency and community, I'm getting quite a kick out of watching the value drop to 7% of it's peak and the community dwindle.
I just feel sorry for the folks that lost money on this fools errand, there must be a lot of them.