Making the turbines smaller is a bad idea, since smaller turbines don't justify large masts, so they aren't as far above the ground, so they experience lower winds. And the power in wind goes as the cube of its speed, so that really hurts.

The turbine is an implementation detail, not a goal.

The power output is the goal, and justifies implementation details such as whether paying for a tall mast is worthwhile.

Wind turbines have continued to get taller and larger since that was written, so I think the verdict is clear.

Yes. But not for that reason.

They've grown taller in order to reach into stronger wind and thereby produce more power.

Which was the argument I was making?

That the masts are tall so that the ends of the propeller blades won't touch the ground.

No, that a tall mast requires a certain power to justify its cost, which requires a certain swept area, which requires blades at least a certain length. It makes no sense to put a small turbine on a tall mast.

Pinwheels demonstrate the viability of other designs. I've seen stories about "microturbines generating power from extra water pressure" in city water systems; why wouldn't "micro-wind" be a viable power source for a number of applications?

We've got decorative windmills in yards everywhere; they spin fast enough to eat bearings. they could just as well well be pushing electrons with that force.