People are inherently obnoxious. At the same time, it was more likely to be a thoughtless comment. He may have been wondering whether you and your dh provided an enriched home environment. I think that your educational background and hobbies would have more bearing than your SAHM status. A single question may be interpreted multiple ways. I usually give people the benefit of the doubt and ask for clarification. If they are clearly making obnoxious stereotyping/generalization, then I would call them on it.
