As an intelligent person who has many intelligent friends, I would not want my children to go to a school where intelligence is frowned upon; nor to associate with children of the type of families that promote that (joking about the associating part). I was in such a school only for high school and it took me years to recover. Unfortunately, many schools in the NY/NJ area seem to be that way these days.
There are two issues here – whether inclusion is a good thing, and how to address the situation if it’s not. If I had the time, (and I still dream I will some day) I would like to start a school for families that are ultra-frum but do not wish to promote mediocrity in every area other than learning.