That's interesting I don't think i would dispatch the aircraft with a broken generator, even though the MEL says you can.

You would be quite surprised at the amount of equipment that can be inoperative and the flight still dispatched...

A gen failure would probably only reduce your ETOPS allowance, from say 180 minutes to 120- which means most flights are still doable. You'd have to work with dispatch to plan a different route (if necessary) and do a fuel re-evaluation.