I understand many Dota player's concerns for creep kill gold etc, but from the perspective of gameplay, if you kill twice as many more creeps as the enemy Demigod, then you should be dominating the map. It isn't always about gold reward, pushing their base is a reward for mass creep killing.
I agree to this, in theorie!
But you miss a valuable point: The reward for pushing better comes very late-> winning the game.
Beside winning the game there is no reward for pushing better.
If your creeps would get stronger if you push more, their towers get reasonably weaker etc. than you would get a reward.
Now this leads to a redicoulus situation:
Team Light pushes the first 4/5 of the game because they play better.
In the last 1/5 of the game team Darkness puts all their gold (and they earned nearly as much as team Light because of this system) in creeps and then they get a little luck and own the enemy demigods and win!
It's as if only the goals in the last 10 minutes in soccer count for the win!