Rabbi Maryles, two things:
1) For all the ideal talk about only accepting ‘gerei tzedek’, ‘impure’ conversions done for the sake of marraige have been a common, if not often mentioned feature of the Jewish landscape for generations. No-one encouraged it, of course, but it happened anyway, and no-one dared revoke the conversion on those grounds. Indeed, the infamous Langer case was just such a conversion. To this day they take place even among the most extreme of Charedim – just quietly with ‘plausible deniability’.
I believe I saw it mentioned in an article by Hillel Halkin that while male Jewish genes remained roughly the same, there was much more ‘foreign’ female genetic material implying that there was a great deal of ‘conversion for love’, and not all of them were out of ‘pure’ desire to convert to Judaism. Unless you want to open a ‘yihus’ pandora’s box in which no-one will come out looking good, this is one attic best left locked.
It is of course a huge bedieved (that should not be revoked post-facto), but that is precisely the situation now – a serious bedieved. People like Rav Haim Ozer Grodzinski, Rav Dovid Zvi Hoffman et al didn’t bend over backwards to allow such conversions due to halachic laxity h”v; they did it to make the best of a bad situation and prevent mass assimilation. The same is true here.
2) The question here is really this: to whom do the halachic authorities see themselves responsible? The frum community only (however they define it) or all of klal yisra’el? If the former, then it makes sense to hold like Rav Elyashiv and insist on all the standards of the community. If, however, they see themselves as responsible to all of klal yisra’el, including the traditional and the secular, and care about preventing them from assimilating halachically, then it makes sense to stand with Rav Drukman, or at least ROY.