Df68,
Look at it another way; most ME ac don't need to bother with Low Level or Stores dropping. Why not have an ME trainer that can teach jet, glass cockpit handling and leave all that pesky LL/Para/Tier3+ trg to the prop boys on the frontline?
Cynically I would suggest that it just forces the frontline types to take on more of a trg burden whilst the MFTS contract provides the barest of essentials.