I don't get that mentality and I'm glad I don't have to live with it. What instruments are real and which aren't? What are the criteria? What musical education and/or skill level does he have on which to base the judgement? I couldn't stand that back in my opera days either.. judgements passed by critics who could never sing a single note on what is and isn't proper, what should and shouldn't be. People with way more talent than me couldn't stand it either, but somehow they put it with it anyway, or took no notice.
But yeah, that kind of judgement really grinds my gears and always has. Is it part of why I chose uke? I'd like to think not....
Hopefully one day your husband will be more supportive.