Why There is no Al Hanissim in Al Hamichya

Although we mention Shabbos and Rosh Chodesh in the Bracha Me'ein Shalosh (i.e. al hamichya) there is never a mention of Chanukah and Purim. Why not?

I saw in the Iggros HaGrid (Berachos 3:13) that Rav Soloveitchik addresses himself to this question. He explains that when it comes to Shabbos and Rosh Chodesh, the days are mentioned in our tefillos because the days themselves "deserve" mentioning. The inherent kedushas hayom of the day is mechayev hazkarah. Thus, these days are mentioned even in the Bracha Me'ein Shalosh. However, when it comes to Purim and Chanukah, there is no kedushas hayom. The mentioning of al hanissim is not due to the day being mechuyav in hazkarah. Rather, al hanissim is said as an expansion of the bracha of hodaah. Once we thank Hashem in Modim it is fitting to mention the specific miracle of the day. This explains why Chanukah and Purim are not mentioned in the Bracha Me'ein Shalosh. The Bracha Me'ein Shalosh is essentially a "shrinking" of the real Birchas HaMazon. The whole point is to abbreviate, not to expand. Thus, to expand upon Me'ein Shalosh by mentioning the nes of Chanukah or Purim is not appropriate.

I heard that there is also a Brisker Rav that addresses this issue. Does anyone know where it can be found?