The argument that wind was more offline than NG conveniently ignores the fact wind was deliberately not winterized bc the plan was for wind to go offline and be substituted by NG.
Imagine if a father agrees to pick up the kid instead of the mother, and then doesn't show up. Neither parent showed up, but it's 100% the fathers fault. So yes, wind was down, but it was never expected to be up. NG is the one that underperformed. NG and wind were both down, but it's mostly NGs fault.
And no, it isn't an inherent flaw in wind generation, it works fine in Antartica, Canada, Alaska, Iowa, Denmark, Sweden, and many much colder place.