How can a map be unfair if it's mirrored? Same chances for both teams, and if you lose that means it's your own fault and that you didn't play it the right way.
You actually think that if something is symetrical it's automatically balanced?
The DG that has the upperhand can monopolize the single lane and make it impossible to make a comeback. If the enemy has QoT constantly bramble shielding him he never has to leave the lane except to get better items, which he will probably only do after killing you, so by the time you respawn he's back and with better items. On a bigger map I could avoid him and farm creeps in a different lane, but here I can't, so the game becomes 40 minutes of me constantly retreating behind my towers and watching him slowly push up my lane.
The only "right" way to play on this map is as Rook or QoT.