Almost everyone rational will buy the cheapest fare available.

Yes, there may be a handful of people who will buy more expensive fares, or premium fares for whatever reasons. But in most cases those fares are not bought by people. Those fares are bought by employers/clients/corporations/etc.

AC has clearly said to their own flyers: unless you are a corporate backed flyer and thus pay double for Flex over Tango, you will not be getting points, its that simple. They have clearly made their policies clear that they dont want any out-of-pocket elites.