"Traffic is not enough to make any real money"

I don't think it's possible to make any universal statement about it. We could make guesses at the ratio of how many people with this business model become successful with it or not (this depends on your costs and profit objectives of course). But it certainly can be done.

The "profit objectives" part of that is pretty important. What do you consider "real" money. On the low end, there are a lot of people making salary-level income on content driven sites + adwords. Personally, I'd be pretty happy with that as a start (freedom) and go from there.

I would rather have the traffic and not need it than need the traffic and not have it.

The poster was talking about his project's traffic, not traffic in general.

If you have lots of highly qualified niche traffic -- the kinds of people that advertisers actually want to reach -- along with a solid in-house ad sales team, you can make quite a bit of money off even a moderate traffic site.

If you have tons of traffic, but you know nothing about the audience, you will get very little money for your ads. Why do you think the washingtonpost.com has to run ads for home refinancing and mesothelioma ambulance chasers? Because there aren't many advertisers willing to pay a premium to target "any schmuck reading the newspaper."

Advertisers aren't stupid. CPM rates have basically been comditized unless there's something special about your site or your advertising model/targeting.