If it were that simple, I'd be in that camp too. But the problem is that I don't think you can divorce the issue of female pay from lingering sexism in American modes of the thought. It remains true that "woman's work" is devalued in American culture (when it is paid at all), females often constitute "invisible labor" that is just assumed to be available at all times. Formal antidiscrimination laws allow us to remedy the most egregious manifestations of this (such as unequal pay for the same exact job), but it does nothing where the jobs are different and have been laced with gender-based tropes that positively or negatively effect their value.
Is it possible that all "female jobs" would still be worth less than "male" ones if both were stripped of their sexual tenors? Possibly. But the problem is we have absolutely no idea. However, at best, the invisible hand would seem to indicate randomness--that is, if we've truly transcended sexism, then "similar" formerly male and female jobs might not all pay the same, but there wouldn't be a discernible pattern where one is consistently worth more than the other.
The argument that women are paid less because of pregnancy and such also doesn't hold water. First of all, it makes at least as much sense that the labor would be worth more because it is scarcer--assuming that these studies are adjusted for hours worked (which seems elementary), the built-in absences mean there are, on average, fewer women available for the same quantity of work (since there isn't anything that shows female jobs require less productivity than their male equivalents), and thus the reduced supply should drive prices up. But more importantly, this reifies one of the key points made by radical "second wave" feminists like Catherine MacKinnon--it acts like motherhood and pregnancy should be seen as freebies worth nothing--a devaluation if I've ever seen one.
Also, riffing off what PG says, I still think that the equal pay/equal work stance is more controversial than the opposition to Wallace. Again, this isn't because I think Wallace is less defensible, indeed, considering I'm a church/state zealot I'm probably one of the biggest supporters of Wallace there is. Like PG, I consider myself to be a social liberal and economic moderate. However, my generic line of thought is basically the following: If you asked the average American the following two questions:
1) Woman are paid an average of 60 cents for every dollar a male makes. Do you think that the government should try to reduce this disparity?
2) Alabama tried to reincorporate prayer in school by passing a law allowing voluntary, silent prayer during a mandatory "moment of silence." Do you think this is unconstitutional?
I think far more persons would fall on Roberts' side on the latter question than the former. Hence, I consider the former to be more "radical," notwithstanding my stringent objections to the latter.
PS: I'm not entirely alone. Suburban Guerilla also seized upon the equal pay issue for specific condemnation. Kevin Drum just wants to know what's so much more radical than this that the Bush administration refuses to release the memos containing it.