If the phrase is misused 9 times out of 10, then redefine it. That's the hacker way.
Descriptivism lets language evolve. Prescriptivism (people trying to push it back) is part of that evolution. According to your principles, you should just accept it as the way the language evolves.
There's a reason why majority rules isn't always appropriate. It's because often the majority can be wrong. We won't redefine the answer to the Monty Hall problem just because 9/10 people get the wrong answer.
If we're constantly redefining words and meanings, then why have definitions at all?
Having said that, I still prefer to use it correctly.