It's certainly not the way I would use "self-define", since those doing the defining are not the person being defined, but maybe I'm just reading it incorrectly?

"It is not the way anyone would use self-define", says sjmaxq.

But, with respect, that's the point, sjmaxq.

This individual is trying to say something quotable. You don't say something quotable by saying something everyone else says.

You say something everyone else doesn't say.

That's how you get quoted.

Savvy politician.