I agree that the Hobo Wave is a massively destructive attack, but I think it's also balanced by the fact that, if you're recruiting thousands of Hobos, that's hundreds of thousands of Alcohol you aren't putting towards upgrading your buildings.

1,000 Hobos is an investment of 400,000 Alcohol. There's literally nobody you could hit with your wave of Hobos that would give you a profitable return on your investment, as 100% of the Hobos you use in an attack die. Even if you blitzed somebody so hard that you recovered 400k Alcohol, you still lost all the time it takes to recruit that many Hobos, and all the resources you could have generated had you put that alcohol towards Drug or Weapon production, and if you want to do it again, you have to invest all the alcohol you earned from that raid. It's fine for one massive blitz assault, but it's an unsustainable tactic unless you're throwing Steem at the game just to buy your way to victory. :)