Not to mention it can break stuff. If QA tested everything with the debug stuff being on the console but temporarily hidden, that's how you want to deploy it as well, otherwise you're gonna have retest and surely fix a bunch of stuff before deploying.

Yes yes, systems should not act like that, probably means everything is too tied together. But real world systems do act like that, especially in things with not too high stakes and with high focus on shipping stuff quickly.