Yeah, that was just badly worded. Didn’t really think it through either. Let me clarify.

You don’t want to spin the wheel too fast, because that’s going to make people sick. To get around that problem, you need to compensate by making the wheel bigger. More specifically, it should be hundreds of meters in diameter. That means it’s going to require a lot of construction materials, and that gets really expensive to build and even more expensive to deliver.

Normally, space things are built to be as light as possible. Building stuff out of thin aluminium, magnesium, titanium and carbon fiber just won’t be good enough unless you make those structures thicker. The materials are good enough though. If you could launch stuff up there for free, you might as well use steel cables and they would be strong enough.

Nevertheless, it’s still a pressurised donut, and that puts a lot of stress on all the parts, which means you can’t build it out of paper thin titanium. The rotation is totally fine by comparison, since that doesn’t add too much to the stresses.