It is hard to think of a better example of what is wrong with Israel's policy towards the Palestinians than not allowing Fulbright scholars to leave the country to pursue their studies.
What exactly does this accomplish? To date, there is no indication that the Gaza scholars are involved with terrorism. What would acting decently and humanely cost you?
People who win Fulbright scholarships tend to be leaders in their society. Israel's decision to deny these people a very prestigious scholarship by not letting them out of the country is going to cause long-term resentment. Considering the other ways the Palestinians are being treated by Israel, it is probably nominal in its impact.
Not letting people use their Fulbright scholarships is wrong and not strategic. The people in question are not going away. It would be just a little thing to let some scholars accept their scholarships. But for some reason, that is too much for Israel.