Not so. The designs for the Bernal sphere, Stanford torus, O'Neill cylinder, and other designs calling for nothing but ordinary metals and glass, would be capable of supporting tens of thousands. Carbon nanotubes may make construction of space habitats easier, but they aren't necessary.

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"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort