The only situation where I see this happening is where the development and improvement of Bitcoin stalls and doesn't keep up with other technology that is coming - the biggest threat right now is quantum computers that could render encryption useless if we don't find answer for it.
There's always a solution to every problem and every little thing in this world has their own weakness. Bitcoin might be weak against quantum computers but even quantum computers have their weakness. Quantum computing can be countered by post-quantum cryptography. Today, the algorithms are breakable by a large enough quantum computer. It's good that they just don't sell quantum computers to people. Quantum computers are only used for much better stuffs. Breaking bitcoin down will just lead to the price of bitcoin going down. Thus, using a quantum computer to hack bitcoins will result to nothing but bitcoin itself going down. There's no gain in money or anything.