Would he still take the qualification if he knew he would never get work as a result?
If so, why not encourage him, if the cost is not preventing you from doing things that are objectively more important? Education is about far more than employment, and many older people do courses for their own pleasure with no expectation of employment as a result. It may be that your husband feels that he has to say he hopes to get work from the course, as many older people have a very transactional view of education, and he might expect to be criticised for just wanting to do it as opposed to needing to have the certificate.
After retirement, I did another MA in a subject I love, just for the love of it. I am happy to teach others about it, and often do so on a voluntary basis, but I don't want to be committed to even part-time paid work now. A relative of mine qualified as an accountant on retirement, after a career in engineering. Again, he has no interest in employment, but does the accounts for a church group, and helps friends and family who have small businesses. It's not unusual.