What's that? Hunter Bow drops off the first boss? Hey, let's boot all the hunters right before we engage the final boss to make them have wasted all that time for nothing.
Yep, that wouldn't be griefed at all.
There is no problem with how LFR is set up. The only problem is the people who run it. Whenever you mix elitist douchebags, mouthbreathers, afk'ers and once a month casuals and put them in the same place, there's no way it will end well whether it's LFR, LFD, Battlegrounds, your job, Pokemon, or Monopoly.