Dereliction of duty
As dog owners we are supposed to remove the feces of our dog(s). You can find bag spenders at many places. And you will not make friends if you don't do so. (Some cities will fine/sue you.)
Equestrians should/must do the same. But some derelict their duty. Like this one from a nearby ride stable.
Thanks to Marlieske for hosting the Derelict Sunday challenge.
PS: if you ask Google to translate "doggy bag" into German it will only offer "Hundekotbeutel", which of course is meant for other left-overs than food :)