Patur aval assur:
When discussing this, or any issue that is not black-and-white in the poskim, there is little purpose in bringing in “Modern Orthodox” views.
We are approaching Matan Torah, and are in the midst of learning Pirkei Avos, which begins with the Mesorah from Moshe Rabbeinu and on. Our celebration on Shavuos is, in a large part, the unbroken chain of our mesorah that we have all the way back to Moshe Rabbeinu.
Unfortunately, since the “MO” broke with our mesorah, as that same Rabbi JB Soloveitchik himself admits, their “opinion” on these matters is not relevant.
Second, biNidon diDan, Zionists have, of course, a vested interest in trying to defend their idolatry. So that quote from Rabbi JB Soloveitchik is par for that course and also does not take into account the points quoted above from gedolim.
If you want a legit opinion against daas Torah, find a true gadol who holds that, if you can find any that do so.