Let's ignore JP's basic underlying arrogant assumption that the Litvak Yeshivas of the 19th century represented the ideal and eternal pinnacle of Judaism. Never mind that this form of Judaism represents only a small percentage of living Jews today.
I remember sitting in on an argument among my relatives almost 40 years ago. They were discussing whether or not people should be doing bat mitzvah celebrations. Its hard to believe, just 40 years ago in the US, Bat Mitzvahs were almost unheard of in the Orthodox community. Only radical, bra-less feminists advocated them. Why should boys get to make a big splash for their 13th birthday, and not have something equivalent for the girls?
Now, in the mainstream Orthodox community, a bat mitzvah celebration is assumed. Some people do it more modestly than others, but nobody I know of would dream of not doing it at all. This is a simple example of "drift" in orthodox practice and attitudes, the occurs in parallel to shifts in western, liberal and humanistic thinking. It them becomes an inseperable part of Judaism and Jewish practice. There are many other examples of this shift, including the training of women's rabbinical court advocates, poskim, and teaching of girls talmud and mishneh in school and yeshivas. Furthermore, many poskim are working on halachic solutions to the "agunah" problem of women failing to get divorces from their husbands and thus being "stuck". My recently married daughter signed, along with her intended, a prenuptial agreement intended to prevent this scenario from occuring.
Another logical fallacy that JP uses is taking the rabbinic responses to problems from 100 years ago as though they were applicable now. He ignores the fact that even Heredi rabbis give psak halacha on the basis of current conditions, not for those that no longer exist. (I remember reading that Rabbi Kook opposed giving women in the yeshuv voting rights!) It is entirely possible that rabbinic ruling were very progressive in their day, and had those rabbis been living now, would rule entirely differently.
The obvious danger is being stuck in the past is that you make yourself irrelevant. Of course a person can choose to do so if he wishes, but to impose it on others in morally wrong.