Every company I have worked for has a certain number of people that are not capable, or willing, to leave the sanitary facilities in an acceptable state.
From people actively soiling the facilities, to people not giving a fuck about leaving a mess (making a 'seat cover' out of tp, then leaving it on the floor; not cleaning after themselfes), to people with a 'not my job' egocentrical attitude. Those are studied engineers with good salaries, workplace stability. In Europe. The facilities are nice, bright and clean. Until those people leave them...
From these lifelong experiences, I would guess there is a certain, not so small amount of people that are secretly incapable of altruistic behavior. For numerous reasons. Those ruin it for the rest of us.
For this reason, as brutal and as it seems at first glance, I would really like to see such people identified and punished harshly for their parasitic selfishness.