For example, 
one response agreeing with the above twitter thread gave a very specific example of the 5e being unbalanced and not supporting DMs: random encounter tables that are not balanced for party level, so that 1st level characters have a chance of randomly meeting a manticore, which will tpk them.  Because players will have their characters fight the manticore, rather than parlaying or running away.  Is that what balance means?  And if so, should a design ethos focused on balance and explicit and extensive rules underpin the game as a whole?
Note: this issue probably doesn't matter to most 5e players, and so perhaps shouldn't even be a concern for the revised edition.  Carry on.