Islamists did join the political process. They won. Look where it got them. Egypt's generals used their friendships with the courts to block reform and when Morsi tried to work around it the military and their backers screamed about the Brotherhood trying to take over the country for good. Islamists have learned the political process means nothing.
EU's Mogherini in Tehran to talk nuclear deal, regional issues (Reuters)
from the article: EU to review relations with Egypt; Muslim Brotherhood vows more protests