[Chris2048]

The question isn't about " hav[ing] someone over for dinner"; but whether you let them use your bathroom.

Sounds like you have a different attitude wrt your own, private facilities compared to the public, common ones. Maybe the difference is you don't have to clean the public toilet?

[i_haz_rabies]

The difference is home vs not home.

[ksdale]

I think you may be overestimating the difference this distinction makes to the minimum wage person who has personally clean the bathroom.

[Chris2048]

You can highlight any difference to justify it; but what difference does "home" make except it it precious to you vs the commons which are not?