I don't mind the SAHM's a bit. In fact, my wife, who works a FT job in Accounting (though she's out right now for the summer since we just had a new little girl!) would really like to be a SAHM, and I would like for her to be, as well. However, some things I have found from talking with people or just overhearing conversations are this:
1) Some (not all, not even most, but some) SAHMs think they are just a little bit "better" at being a mom than moms who work. Now that is a load of crap. My wife manages to do in a week what a lot of SAHMs do in a week, and manages to do it in a shorter time period b/c she has to work around 40-45 hours per week where she is tied down in a different location. My wife can work circles around a lot of the SAHMs I know!!
2) Some (not all, not even most, but some) SAHMs just can't fathom why any woman wouldn't want to stay home with their kids. Newsflash: not every working mother WANTS to be a working mother! Some (as with my wife and myself) have to do it from a financial perspective, just to make ends meet. I hear this a lot from wives of husbands who I know make well over $100k per year, so I imagine from that perspective, maybe they don't realize the struggles that other families who don't make that much go through. It breaks my wife's heart that she can't be there all the time for our kids, and I don't like it any more than she does, but right now, there's nothing more we can do about it.
3) My wife hates, I mean REALLY hates, when her friends who are SAHMs complain to her about how tired they are, that it was a rough day at the pool, that the kids were cranky today, that she had to go to the grocery store, etc... You know what? Too bad. Live with it. Do you really think you're any more tired than my wife, who has to be at work before you're even out of bed and won't see her kids until dinnertime, after working all day, only to have to come home and take care of them and the house until she collapses from exhaustion? SAHMs, please be sensitive to what you complain about, especially to those mothers who have a job outside the home that ties them down.
4) It still amazes me how the behavior of some SAHMs' kids they think is so cute, is actually atrocious and obnoxious. I have seen dogs with better manners than the kids of some SAHMs (for that manner, I have seen dogs with better manners than the kids of some working mothers, as well, but stay with me), but they think their kids walk on water. Some of them are socially unadjusted, get scared around anyone except their mom, and couldn't form a coherent sentence to save their life, relying on mom to do it all. Then they wonder why little Susie isn't doing well in kindergarten and can't make friends. I am often glad that my kids are very well behaved (thanks largely to my wife who works with them a great deal), very well adjusted and function well in school and are extremely smart. I'm not saying that is the case for all working mothers' kids vs. SAHM's kids, but I do see a lot of it around where I live.
Bottom line - both mothers who work outside the home and SAHMs work very hard, and neither is better than the other. Enjoy the situation your in, don't brag about it (or complain about it), but live your life to the fullest and have as much fun with your kids as possible. You have them for only a very short time in the grand scheme of things.