You're cultivating a bad sound.
That is what my tuba professor at Northwestern, Rex Martin, used to say whenever I would play any note without using my absolute best sound possible. That included quickly touching a note to get a pitch in my ear before buzzing. It also included ghosting a note down an octave before playing a note in the high register. He made me apply the concept to every single time I ever played anything and it is some of the best advice I've ever received in my career.
Every time you play anything you are reinforcing something.