I did notice the non earning fare basis can be higher price than earning fare basis. However when airlines offer a new fare class that are not automatically included until partnership agreement is renegotiated. Aeromexico was another example of a program, where even discounted Business class didn't earn points.

Hainan has always been weird. For instance one way 11/16/17 SJC-PEK, The lowest fare Economy Saver is $369 and is a W fare earning 50% but the next one up Economy Basic is $519 and is only an N fare so earning 25%. Yiou have to be extra careful when booking with HU.