I would tend to think that with MRs being such a tiny segment of the flying public airline management does not give it much thought either way. More front line employees often seem to be enthralled by the idea of people flying solely for the purpose of collecting status earning miles. Management has more pressing issues to be worried about.

If the airlines really wanted to get rid of all MRs (thought it was a worthwhile effort to undertake) then rid themselves of same day cheap fares, DEQM promotions, multi segment booking and the like.