It all depends on the value of what you're trying to secure, and if an attacker knows the value of what's in the account, and if the attacker has access to hints about the password you used to narrow down the possibilities. The researchers knew all of that info and they still didn't want to bother trying to crack the password until they found an additional way to narrow down the possibilities even further.

There's no such thing as perfect security. A lock only needs to be strong enough to make it not worth breaking into for what's in there