Open diffs are designed with the lowest common denominator in mind. Just like coffee from McDonalds is luke warm (in case you are stupid enough to spill it on yourself).
LSD will cause oversteer and most inexperienced drivers cannot recover from Oversteer. Understeer is more likely to come back to you after your arse has twitched and you've jumped off the loud pedal (stupid thing to do, but what 90% do).
My car has an open diff and traction control. It works as a combination brilliantly. You really only need and LSD or Locked diff if you like doing doughnuts (off course I do) or drive seriously at track days.