Your conclusion doesn't follow from your argument. Cost effective is a measure of the price of the windmill and supporting equipment vs the value of the electricity. Using that measure and allowing the 1.8 penny ptc, they are quite cost effective.
Just set up the BBQ under the biggest baddest windmill and wait for a suculent tenerised pre killed dinner to drop out of the sky.
If you are lucky will get a spotted owl.
Enjoy
An argument absent any facts.