Try to make one and you'll see
Auto-knockback is too strong atm. Melee are OP in some situations that happen regularly, like in buildings, or behind doors etc. As long as you can reach your opponent, you pretty much win every 1v1.
I can understand the fact that melee SHOULD win if they can reach their opponents, but just see some scenarios :
1. Range sees Melee on a street, Range can shoot Melee to death before Melee reaches him, so Melee will just run away or at least cut LoS.
2. Melee tries to ambush Range in a building, Range sees Melee close to him and decides to run away. Why should Melee be able to be faster and kill him ?
The thing is, if Range and Melee are far, Range wins but Melee can run away. If Range and Melee are close, AND if Range has not the adequate equipment (like shotgun/mirkor for example), Melee wins but Range can run away. Why do you want to change that ?