There is total freedom of thought and expression here. Just like in any other place. No discrimination in law. Just by people. If your values are opposed to someones most high and sacred values, they probably wouldn't like you, and wouldn't hire you. Don't you think? It's their choice after all. And as far as this guy goes, nobody has to admit him. It's irrelevant anyway.
U.S. defense contractor accused of copying secret military documents (Reuters)
from the article: Noam Chomsky denied entry into Israel and West Bank