Yes, I understand DG can be frustrating when you have people on your team who don't know how to play.
However, for all that you "did" you failed to take down any buildings (perhaps you left that to just the creeps) personally. That suggests to me you focused more on hero kills than some of the other objectives in the game.
It reminds me of a 4v4 I was playing on Prison (crazy I know) where we had a mass disconnect so it was just me vs. AI. Just for a kick, I decided to go all out hero kills on the AI. I got 31 hero kills and had Ashkandor, All father's ring and other artifacts. I was literally the baddest man on the planet. However, all I did was run around hero killing just to see how how my body could would go.
As the game ended, I was ready to yell victory and collect my favor points (b/c this all started as a MP match). However, it was I who lost.
In all of my bloodlust, I never bothered to upgrade creeps or get giants. The other side did (AI wins!!!). While I was capping all their heroes, just enough giants were getting by to take my citadel down and I didn't even know it.
Another more relevant circumstance last night was a 4v4 win I had on Leviathan last night. We were totally outmatched in terms of hero kills, damage done and so forth. However, my team was better on getting reinforcement upgrades and portal control. So, even though they owned us on kills we had a better war score and won the game once we got to pults (they went all anti hero and had no effective AOE). Our RI just overwhelmed them.
The point is that even though you may have the best stats, you still can lose if you aren't doing the right things strategically.
Maybe you lost just b/c of noob allies.
Maybe you lost b/c you focused too much on being anti-hero and not enough on being anti-building.