I am completely on your wavelength urbandryad. I love work, we are better off, the kids love/prefer nursery, i love my day off each week with them.
Life as a SAHM turned me into a miserable, unconfident prozac-popping recluse (must stress that this was clearly just me - not a judgement on SAHM-dom as a whole)
In fact, life as a WOHM for me is like some kind of Julie Andrews film compared to the alternative.
But I do have the same guilt as you about preferring it this way. It's as if there is something missing in me - why am I not a 'true woman/mother'? Why can't I do it? And I agree with Franny that there is some kind of natural instinct not to be away from the children when they are small, which gives you a niggling feeling that there is something wrong.
So my way of justifying it is as follows:
If I lived in a society/community near my family with friends, parents, neighbours, relatives nearby who also had children, then I would probably enjoy it.
But in an atomised modern society where we don't even really know the neighbours, let alone many other people locally, I found it very isolating to spend so much time in the house alone (with the children).
I;m not entirely sure I am convinced by this, but it works for me!