Are the Iroquois really that bad?

If You start as the Iroquois in or by a large forested area then you have the opportunity to be at the top of the list as all your Civilization's bonuses relate to forests. If you don't begin near a forest and you can't manage to found at least one of your first three cities by a forest: I would be surprised if you could win at any normal difficulty or higher.

I like taking the +1 food from camps bonus as the Iroquois. They often start the game surrounded by camp resources, especially deer. A plot of deer with a longhouse and camp bonus will give you (if I'm not mistaken) 4 food and 3 production. If you get lots of these tiles nearby you can get some pretty strong cities.