Fully intended.
The first ~50 versions of WC3 Warlock had gold/per and gold/round-win rewards.
The community wanted this removed because it resulted in a snowballing where new players in particular would never stand a chance to win later rounds.
I would like to add that you can set and change gold rewards if you want, as well as many other variables during mode picking phase
[Game Start] [Red Required]
To see the different gold reward settings, use command: -constants 2
To see the other ones use command: -c
For example if you wana add 10 gold/kill: -c 12 10
12 = Variable number
10 = Value
Although, as stated above, it's not recommended if you wana have a fair game.