If he is asking you, as your husband, to be more cheerful and less complaining then don't you think you should take that seriously?
I just don't see how he is to take what you say to heart when you may not be willing to do the same for him. He is holding out a big sign with neon lights all around it, asking for change, and you are blowing him off. That also gives him the ammunition to blow YOU off--after all, he doesn't feel validated or that he has been heard so why should he listen to you? Why not just turn to the porn and chocolate. (and, look, he can't be all bad..he has excellent tastes in vices!:)
I agree that this might be a cultural thing but it also may be an area in which you will have to learn a different way to act around him. It just might not WORK to be this way around him.
I can picture two sarcastic and poking-fun Americans at the symphony critiquing the conductor's every move so I do get what you are saying about the cultural thing.
However, if your H is telling you that this area needs change--and he's said it many times--then I as your friend would be remiss if I didn't say, Yo! You might be missing something huge here!!
My husband is big on having a cheerful wife, as well. I resented this for a long time because I thought I never got a break in which to be crabby. I have to say though that the acting as if thing really works. If I act cheerful long enough, pretty soon I am feeling cheerful. Now, I am not cheerful every day but just knowing that my H now has a mental image of me as a cheerful and loving person makes me want to BE that person.
I imagine it must be next to impossible to be cheerful to your H, given what a big fat crab he likes to be, so maybe you could approach him and tell him that you'd really like to address this in yourself but that you need his help--namely that you find it hard to NOT get crabby when he picks on you.
Here is a tidbit for ya: My H admitted (after he stopped doing this atrocious behavior) that at one time he would walk in the door and begin surveying the room, looking for something to b*tch about. Dishes in the sink, toys on the floor, crunched up crackers under the table, whatever. This was when we were having sex a handful of times per year. I asked why he did that and he could not give an answer.."I don't know, I just remember feeling really on edge when I walked in the door and wanting something to pick on." I couldn't tell you the last time he did this--years ago now. So your H CAN change this behavior and I hope he is willing to do his part in order to effect the change that he wants to see in his house and marriage.