With all due respect, that's not going to happen. First because most password managers use local storage, so it's not possible to blanket hack them. Second because those that don't still use absurdly strong encryption and rely on the user having a secure master password--it's not remotely similar to your standard hack a vulnerable web server, steal a gazillion unsalted md5 passwords scenario, so a hack wouldn't result in the kind of data disclosure that's problematic here.
If everyone starts using password managers to remember their essentially uncrackable passwords, then hackers are going to change their methods accordingly. And no system is perfect. The very nature of password managers is a glaring weakness by making all your passwords protected by a single password.
It's like authenticators. When they're not widespread, they offer good protection because attackers go after the low-hanging fruit instead. When everyone has to use one there's a huge incentive to attack it, and that's precisely what you see.
Further, you can't make blanket statements like "that's not going to happen". Previously secure algorithms do get broken from time to time. Or sometimes bugs in the software implementation present weaknesses. Anyone who knows anything about the matter will find this to be nothing new.
There are a lot of intelligent and dedicated people out there interested in breaking these systems, and as a result many people spend a lot of time, effort, and money trying to stop them. Security and complacency do not go hand in hand.