Because he has stated that even if he was removed as CEO by a shareholder vote, he would continue with his plan to shut down GLBSE.

Anyway, there are a few reasons why the vote to remove Nefario as CEO failed. First, he has a 24% stake in the company. Second, he had a couple of minor supporters. Third, most of those that opposed him in principle were already resigned to the course of events and didn't care to actually take a stand, as even if he was removed, he stated he would shut it down anyway.