So, when SAHMs make comments that seem to suggest that WOHMs don't care enough about their kids, it touches on a very raw nerve. Whereas a WOHM making a comment that seems to suggest that SAHMs don't contribute to their family's security and growth, it doesn't really offend because most people don't have that raw nerve about providing for the family.
Also, I do feel like SAHMs are sometimes guilty of making untrue assumptions about the role working mothers play in their kids lives, and what daycare is actually like. And that's fine, there's no reason for you to know what daycare is like if your kid has never attended one. But then don't say things like you know that staying home with you is what's best for your kid (yes, even your own kid). Put your kid in daycare for a few months, and then see if you're right or wrong. At least then you can make that statement with fact to support it, rather than just an assumption based on your own fears about the experience.
And FWIW, I work 10 months a year. I stay home 2 months a year. When I work, I spend about 5 of my daughter's waking hours at work. During those 5 hours, she eats the meal and snack that I prepared and packed for her, and she plays, talks with, and enjoys the company of her teachers and friends. I know what's good about staying home and I know what's good about letting my daughter experience other people. I know that each kid has different needs, wants, and tolerances, and I think good moms do what is necessary to meet those needs and wants within the confines of keeping the whole family operating smoothly. As a personal example, before DD was born, and even when she was an infant, I was sold on the idea that daycare centers were EVIL, and that a small home based center was much much better. For some kids, that's true. Not for mine. She thrives in the center environment. I had to be responsive to her needs over my own beliefs in order to make that happen though, you know?
Sorry for the choppiness, I'm writing on my phone...