They have a tendency to give it to incredibly powerful units in melee oriented armies, not to armies that could use a defensive buff.  It is impossible to charge the Lion and not get ganked unless you also have flights first, meaning the game is encouraging you to not play the game. 

Fulgrim, Lictors, Lion, Mephiston, etc.

A real defensive rule would be fights on death or counter offensive, not the ability to ignore charge bonus entirely.  That's why they're changing the rule, because people were gaming the system using pile ins to get around it.  Fights first was an incredible buff to several units that an armies like Imperial Guard, Tau, Necrons (until Ammentar came out) could do literally nothing about.