Not to say that much smarter people can not add more, but I think a lot of it comes from the view of to him in the context of the book was trying to be simple. Put something in your body, get insulin, do not put things in your body, no insulin. The more hours a day without insulin, the better your body responds. Alcohol is pretty complex and to try to tackle it probably would take a more detailed approach and take away from the message. Alcohol is food, and it effects your insulin, treat it as such. Just guessing of coarse.
Not sure if this is agenda pushing, or looking for actual data. If the latter, I’m down 80lbs fasting OMAD or a four-to-five hour window most days, using ketosis and careful macro counting. Stronger and leaner at 53 than ever in my life, but still drinking alcohol every night with my wife and (much) more on weekends. For me, the biggest impact is sleep quality and recovery. If I over do it, the effect is measurable in elevated heart rate at night and energy the next day.
But alcohol is not a boogeyman. It has a cost, and a benefit, and it’s possible to make tremendous progress on overall fitness while consuming a rather large amount of it.