There isn't anything more important than having time with his kids. Based on their ages they will all be out of his house in 15 to 20 years. I would do all I could to maximize those years with his kids because soon they will be gone and he then can worry about a fulfilling career.
Plus, he needs to give his kids a couple years to get older. Then you can start doing some fun activities with them. It is hard when they are young, but with kids ages 9-14 it is awesome right now because they want to do fun activities that I want to do.