Saudi Arabia allows unmarried couples to share hotel rooms
https://edition.cnn.com/travel/article/saudi-arabia-unmarried-couples-female-travelers/index.html
I can understand that some Muslims obey strict rules such as prohibition of staying with sweetheart in a same room.
But, it would be difficult for non-Muslims to obey the same rules. So, what is needed is to allow non-Muslims to violate strict Islamic rules in the country.
It's better way to preserve Islamic cultures and to promote tourism at the same time.