The European federalists do not have the intelligence to understand that forcing their opponents to work within the system would have diluted their message. It would be much harder for Farage to claim that he opposes Europe if his MEPs were benefiting from its patronage. The federalist parties have helped the Eurosceptic cause. Undesirous of facing such unsanitary views as voting within the committee system, they have overridden the De Hondt system of allocation for committee places in order to exile the Europe of Freedom and Direct Democracy (EFDD). This has been attacked as a "breach of protocol".
So they were so busy blocking democrats, they missed out the Neo-Nazi on the Civil Liberties Committee. Rather like having Saudi Arabia on the Human Rights Council at the UN, though Europarl has the decency to look embarrassed.