I agree with those who say we all deserve respect for doing what works best for our own families, or doing what we have to do! I have great admiration for both working moms and SAHM's.
DH works so much that our family would probably never work if I worked too. There are benefits and negatives to both situations. We have far less arguing over who will pick up or take the kids, or stay home when they're sick, or make dinner, or clean up, and DH has been able to get much higher up than he would have if he ever had to worry about where the kids are. But there ARE major financial negatives, and frankly I get less respect, at home and out.
I don't think it's a rude question to ask at all. In fact when I worked I felt people were rude for
not asking, as if only my husband were the important one.
The only problem is, now that I am a SAHM, although I consider the question polite, I do feel inferior or unjustified with my answer, especially now that my kids are 12 and 14. Most people don't make "What do you do all day then?" a second question, but sometimes I see it on their faces. I do a lot of school volunteering, I take lots of other people's kids to school, I take care of every single thing there is to do with house, home, and family, and I am here when the kids get home and when they come and go all afternoon I know where they are. I take them to their swimming and basketball and piano, and I'm there for every meet or game or recital or after school activity pick-up. I don't say that as if it's something astounding, I'm just saying what I do. But I can't say all that without sounding defensive or holier than thou, and somehow SAHM does not convey what I do.
I really see staying home as a valuable societal contribution, (among others!) but the feelings of inferiority do always pop up when I get the question, as well-intended as it is.
So I am reading the answers with great interest.