MacArthur and those like him remind me of libertarians. They are more concerned with being doctrinally pure than with winning battles. Hasn't he heard that "the perfect is the enemy of the good"?
“and he is continuing with his feud with Catholic/Orthodox Christianity. “
Catholics and Evangelicals will have plenty of time to feud in their shared prison cells.
You can't get it [the means of salvation] partially right and partially wrong. You can't mix the agenda of God and the agenda of the world, and hope to get it right. Doctrinal purity is all there is...getting it God's way, not man's way.