My husband is also a diver, certified in the late 60's. When I learned to dive two and a half years ago, he took the class again with me. We immediately began to have battles over diving, because we couldn't agree on how a dive should be executed. It got way, way worse when I took Fundies and set off on what my husband viewed as a ridiculously complicated and unnecessary approach to diving. As a result, for about a year, I didn't dive with him except when I had to (when we were on vacation, for example).
Fast forward two and a half years . . . My husband has taken Fundies, we're both Intro to Cave, and the only vestige of the diver he used to be is a Cobra console he refuses to part with, although he uses a wrist-mounted depth gauge as well. We can also dive together now without the arguments starting as soon as our mouths break water
It just took time and patience, and him having an opportunity to dive with my DIR friends and with the friends from the shop where we got certified. Slowly but surely, he saw the benefits of the DIR approach, and adapted.