The problem is that there was no wind in the coldest days of December when we needed electricity the most. Building more of something that goes to zero when you need it doesn't help. With huge storage capacity, maybe, but even the author of the article doesn't seem to think storage is particularly practical.
I don't think the suggestion is to replace gas generation facilities with wind, but to concentrate new power generation on wind.
The incremental cost of keeping a gas generator working is very close to zero compared to all the other expenses involved in building the plant and buying gas to burn in it. We can keep all our gas infrastructure around and simply use it less often if we have more wind.
