The New York Times‘ David Leonhardt socks us with a stark reality in today’s column, “A Market Punishing to Mothers.” The last three women nominated to the Supreme Court — Elena Kagan, Sonia Sotomayor and Harriet Miers –“have all been single and without children,” he writes.

Kudos to Leonhardt for making the legal eagles symbols of “gender inequality” — evidence of the notion that women must sacrifice to succeed. But I have to call him on the heavy blame he places on corporate America and U.S. government policy for the dearth of women at the top. Are women such victims, with hardly a chance to compete? I don’t think so.

At a Most Powerful Women lunch that I recently hosted at Fortune Brainstorm Tech, a group of some 40 female execs (and a few well-intentioned men) chewed on the issue. Many agreed: Women who could be Fortune 500 CEOs someday often don’t chase the dream because they know there are better ways to fulfill a career. Particularly these days. In Gallup’s 2010 Confidence in Institutions poll of 1,020 adults, “big business” ranks near the bottom, at 19% alongside HMOs. Just one institution rated lower: Congress, at 16%.

Small business comes in at the top, right behind the military (No. 1 again). Indeed, entrepreneurship lures a lot of women from the Fortune 500, at a higher rate than it attracts men.

At the Fortune lunch, MediaLink President Wenda Millard noted that many young women are turned off by large-company execs’ all-consuming careers. Millard herself moved from big to smaller. Once a senior exec at Yahoo and later co-CEO of Martha Stewart Living Omnimedia , she is now a partner in the marketing and media advisory firm.

And some high-powered women turn down promotions, or view them reluctantly at least. Martha Josephson, an executive recruiter at Egon Zehnder in San Francisco, said she finds that women, more than men, don’t answer her calls. Moreover, women stay in jobs longer before leaping to a bigger gig. “It’s loyalty and being risk-averse,” said Gerri Elliott, an EVP at Juniper Networks , noting two reasons the race to the top remains tilted toward men.

Admittedly, it is the privilege of the top ranks to select an employer with a level playing field. Elliott, who was one of Microsoft’s senior women until last year,  joined Juniper largely because CEO Kevin Johnson runs a company where 38% of the senior brass is female. That’s about three times the average in the Fortune 500. Johnson, whom I interviewed at the lunch, said he formulated his philosophy during his long career at Microsoft: “Any team that has diversity will innovate better, avoid group-think, and be more intellectually challenging and stimulating.”

I happened to have lunch today at another company where the boss gets it: Bank of America . New CEO Brian Moynihan has 12 direct reports; five are women. Lisa Carnoy, co-head of global capital markets and a mother of four, told me over lunch that she’s in the right place: “The bar for women is generally higher, but if you’re a hot-shit woman, it’s great.”