Once I visited Soyambu temple.

With that tax, there is toilet for Nepali people too and we can enter world heritage sites without paying extra money. 
Anyway, I don’t disagree with you. I think Nepali toilet should be equally clean too and we definitely need more toilets. But, I also think there should be separate toilet for Nepali and tourist specially in those heritage sites.
Since, tourist are paying good amount of entrance fee to enter those heritage sites they expect basic facilities like good toilet and better facility when they are there.