Wait..what? Your "advice" is for him to tell his wife, no matter what the cost?
I don't think you have any sort of understanding of what his situation is, and how that can affect someone's life/mental health.
Not everyone has the luxury to live in an area/culture/family where being your truest self is encouraged and embraced. Even in the more progressive countries, homophobia and fear of being outed are very much realities. There can be a wide variety of consequences, from being socially ostracized, to jail, or worse. In the case of the person you were referring, he would lose his family.
I don't remember the entirety of what I felt when I hadn't come out, as I was a very early teen. What I do remember, is the consuming anxiety and fear of being found out, as well as internalizing this feeling that I would be utterly rejected. Now, imagine not coming out, and carrying that into your adult life. Except, for some people, the realities of coming out truly can be life destroying.
I know you think you are telling him solid advice, but you aren't. You have an ideal, that coming out is the preferred place to be no matter what. But, that is your ideal, and you've completely disregarded the other person's situation to push your view forward.
What you should try to do is listen to what people are telling you. Then, try to understand.