One, this guy's islamic radicalization has made him crazy (although not in a legal sense). The defense he wants to present is not only an admission of guilt to murder, but terrorism.
Two, this guy is proving the old saying that anyone who represents themselves in court has a fool for an attorney.
One other consideration I would offer is the judge can't stop him from representing himself, but if she doesn't keep a tight rein on him and strictly follow correct procedure she might introduce an error that would be grounds for reversal on appeal.
True that.