Who can destroy bitcoin.? For me its a hacker because hacker is a more about knowledge about bitcoin.
A lot of hackers exist in this world still bitcoin is alive for 8 years now, Hackers can't stop bitcoin unless they have their quantum computers now and making a move to overtake bitcoin.
The thing that will be destroying bitcoin IMO is the people who are using it. Bitcoin is always pumping because of it's users, bitcoin is becoming popular because of it's users, so without user, bitcoin will easily crumble down. Not only that, since bitcoin is mostly based on the demand and supply, without demand, bitcoin will be nothing.