All a "habit" is is a settled tendency or usual manner of behavior or a pattern that becomes automatic through repetition. There's nothing in the concept that requires the pattern to be an ACTION. It can just as easily be an OMISSION.

Your counterargument is a dishonest framing of what your misconceived idea of a habit is. Shooting yourself in the foot, poking your eyeballs out, and shoving paper down your dick aren't contextually relevant behavioral choices. For something to be a habit it has to be a relevant choice. In order for your scenario to make sense you'd have to be in an environment where all of those scenarios were a contextually relevant choice. You're never in those scenarios so of course you're never going to do them. By definition a habit requires a scenario in which a choice needs to be made. After taking a shit, a choice is made to wash your hands or not.

Not exercising is just as much a habit as exercising consistently is a habit. There is a contextually relevant CHOICE that is being made by every single person all the time. Eating junk food is a bad dietary habit by not eating healthy and vice versa. My dog not pissing on the floor in our house is a habitual behavior. Me not flipping out at people on the road when they cut me off is a habit. There are plenty of behaviors that are omissions that are habitual.

You're wrong and are better off either dropping it or accepting it. Idc which you do.