Why couldn't Krall and crew repair the USS Franklin when Scotty and Jaylah could?
Jaylah is not Starfleet (yet) but was still able to work on USS Franklin, and was eventually able to get it running with the help of Scotty.
Why didn't Krall do that instead, using surviving crew members and/or drone workers, instead of choosing the more extreme option...
Krall, being a Starfleet captain of the ship, should have known more about the USS Fraklin than Jaylah or Scotty ever could in the limited time at the crash site, right?