Logic has everything to do with it.

Flights over 2000 miles earn 180, flights below 2000 earn 60.

Cheap fairs - *up - book either into biz class or first, depending on the model of the plane and if it is a 2-3 class plane.

if you get such a fare, and iti s a three class, then you get biz, the biz code and the biz tier pointe.

over 2000 miles: 120, under 40.

it is complicated but it is fully logical.