I promise you they don't.
It's not (just) the condition of the paper, it's the side of the tub that's showing. That's not a fresh mess. It's a smeared on patina of gross - and it's DRIED. I'd rather see fresh streaks of crap than what is there. Fresh crap is understandable - that's not, and ain't no way snake painted it on that evenly, either. It's just a sloppy job of cleaning and probably over a long period of time.