Reply To: Women and Grace

The bizayon would be like the first half of Rashi – the guy’s an utter failure for not knowing/learning how to bentch.

Your pshat about “mitvos aseh shehazman grama in general” might conceptually be able (to combine with your original suggestion as to the purpose of the braisa) to alleviate (some of) the dochekness pointed out in my original question, but I definitely don’t think that that’s what either Rashi or Tosafos is saying. And also, it would then have nothing to do with Birchas Hamazon. It would simply be that it’s always less than desirable for a woman to be motzi a man by any mitzvah, even when they have the same chiyuv. And why should it be true that having fewer chiyuvim has any relevance?