Where do i start?! Those C+ or preferred seats are given away just before boarding starts, to non-loyal non-status and equally BE customers. Why should those seats to go those passengers?!?!?!?! They are no more entitled to them as per your argument!!!

The solution to this BE problem is simple. NO ONE in BE get any seat assignment until boarding and they assign seat from good to bad to high to low status/fare class - all in one process. So no one feel they are cheated and the small perks, say rarely available C+, or Preferred Seat that freed up due to that occupant got upgraded to C+/F, goes to more loyal customers.