Reward those who pay more for their seats:
<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Members traveling on Full Y fares will continue to earn a 50% bonus towards Elite status. Members who purchase business fare types and/or travel short distances can earn Elite status with as few as 20 Elite Qualifying Segments.</font>
This to me makes a lot of sense. Use a carrot, not a stick. NWA has a lot of class in my books.
With the changes to segments on CO, I would suspect that CO elites will have to switch to NW in order to get the full miles, not just fly NW.