mik5:
Much more important than the so-called “prohibition” of not eating gebrots is, for example, to keep yoshon and to be makpid about zmanim (for Mincha and krias Shema).
You do realize that these options are in no way mutually exclusive…
Just because X is more important than Y does not mean that Y should be completely disregarded. And I hope you’ll agree that keeping to a minhag that is several hundred years old does have value.
It should be noted that with all due respect to the Chofetz Chaim, Rav Moshe felt that if there is a machlokes between the MB and the Aruch HaShulchan, we should go like the Aruch HaShulchan because he was a rav and the Chofetz Chaim was not a rav. However, the yeshivishe velt is noheg that the MB is the posek acharon.
I’ve been told that the Chazon Ish considered the MB to be the mainstay of Halacha, but this view does seem to be the standard even amongst non-ChazonIshniks.