Sometimes these forums are the only safe places women have to say how they feel deep down inside. It is a way to let out the frustration so that it doesn't get taken out on their children.
I would venture to say that even the most perfect Mom has her moments of wishing "I weren't a Mom right now". Like when she has the flu, and so does the rest of the family, the baby is throwing up everywhere (and so is Mom), the 3 year old is taking advantage of that fact by climbing up on the kitchen counter to get the cookie jar - and it falls and breaks into a bazillion glass shards, so he starts screaming, and Mom has to clean it up. Dad is knocked out on codeine cough medicine (or at work blissfully away from it all)...you get the drift.
Everyone needs someone to vent that deep, dark secret to. Doing so online to faceless strangers is easy - because ususally there is no jufgeemnt and sometimes there is someone else who has been there.
I know that with my oldest who has Asperger's I find myself (very guiltilily) wishing that he had not been born, or had been born "normal", because it is so exhasintg at times. I have to MAke myself count the good things that go along with his differences. And there are good things, it just takes looking with a different eye sometimes.
For you ladies that are suffereing - just remember this baby/toddler phase doe not last forever. One day they will be able to take care of themselves more and be able to interract with you. You might be able to enjoy them more then. Some parents just do better with one age group than another.