The main blame for such counter-progressive impacts must, of course, rest on male privilege. Men who advocate environmentalist lifestyles can conveniently forget how their programs depend on exploiting women's labor. But in reflecting on my own "oh yeah, I hadn't thought of that before" reaction, it occurred to me that there was another form of privilege at work -- progressive privilege. Progressive privilege consists in a failure to recognize how things that you advocate will play out for other people due to a mistaken assumption that the world is more progressive in other respects.
Take the case of environmentalist eating habits. My wife and I are (lax) vegetarians and members of a CSA, among other lifestyle changes advocated by environmentalists. Clarke's post highlights how these practices, done in a context of a traditional gender division of labor, can increase women's oppression. However, I would venture to say that my household has a comparatively progressive division of labor. With respect to food issues, I do all of the meal planning and cooking, a good majority of the cleaning, and at least half of the grocery shopping (including picking up our CSA vegetables). Because I'm most familiar with how eco-friendly eating works in my own gender-progressive environment, it's easy to forget how it would play out for other people.
Polyamory/polygamy is another example. When I think about people with multiple partners, what springs to mind for me are several friends (all women) who have/had multiple partners in the northeast/west coast liberal fashion associated with the term "polyamory." In that context, loosening the norm of monogamy is not in conflict with feminism -- indeed, it arguably supports and extends feminism. But of course the environments in which my friends practice polyamory are unusually progressive. It's easy for me to lose sight of the fact that in most of the country, the prevailing unfeminist norms mean that polyamory would become fundamentalist-Mormon-style polygamy, which is oppressive toward women.
This is not to say that advocating eco-friendly eating or acceptance of polyamory is wrong. Indeed, progressive privilege is rooted in the fact that these things are not detrimental to the feminist cause when practiced in conjunction with feminism. The point is that progressive successes can make us lax about remembering the importance of pursuing progressivism as an interconnected whole rather than as a set of separate issues.