In areas that have lots of electric space heating (not much anymore), when storms come in and the wind blows, heat loss from homes goes up dramatically making the windmill power coincide with the need for electricity. That is a great match. Most of the rest of the time, they are just fuel saving devices, where you still need to invest capital in another form of power plant to carry the main power load.
They do have their place, but it is not a universal fix.
Germany and Denmark have sure proven that. Iowa probably produces the most wind power per capita in this country. We have barely scratched the surface of what is readily available. There is a lot of resistance to wind power though and it has more to do with not liking the people who like wind power than any logical argument. I see a lot of that between the FR and the DU.