It would be deadliest if the bug is exploited within last 1-3 years, where public already hear about Bitcoin and the damage would be severe since making majority agree to perform rollback or upgrade client in short time is nearly impossible.
Things would have fall apart sincerely speaking and Bitcoin name send to mud.
+why the community find this difficult to implement rollback into Bitcoin network?. Cryptocurrencies exchange has been on the news about hacks and nothing has been done to ensure there are mechanism which can allow rollback if there are incidents of such(stolen funds recover from hackers). I think this should be an important aspect the community of Bitcoin Network and exchanges should look into for solution.
If Mt.Gox hadn’t happened, where do you think BTC would be today?
Mt. Gox help the bitcoin community grow bigger. Exchanges become better in their security. Laws become stricter. I see Mt. Gox does it role very good for bitcoin. I am sorry for any people who lost money on Mt. Gox
~~
They also help in slowing down global adoption becasue the news of their hacked exchnage went viral. The team wanted rapid spread of Bitcoin without having the capability to secure investors funds, remember Jed McCaleb gave 88% to french engineers and kept just 12% to himself. Having the control of over 70% Bitcoin trades as at that time was a good one, but there was a huge loss to the community after the hack. This has affected the rapid spread of Bitcoin, hope they pay back the stolen funds.