In an ideal world, people should clean up after themselves. But for the company to leave it dirty despite receiving complaints isn't on.
They don't subject their passengers to filthy cabin (or one would hope not), so why should they subject their staff to filth? Dirty conditions is not exactly great for OH&S either.
Unless, that is, the company is trying to keep their pilots awake by creating a cockpit stink.
(then again, the filth may ferment and create toxic gas
)