I find that when you teach people to knit (I taught my future sister-in-law) and they insist that they're knitting the correct way even when they're not, the best thing to do (and the best way to avoid coming to blows) is simply to agree that they're doing fine. Eventually they'll want to knit neater or faster and you can say, "well let me show you this new way to hold the needles that might help you with that!" Problem solved!
At least your husband created something that he was proud of. Maybe he'll come back to knitting (if your blood pressure can tolerate guiding him again) and do a little better someday!
It's interesting how knitters like us feel the need to "convert" our friends and families.