NetBIOS is just one of the first steps in a system compromise, allowing you to enumerate the host for other possible vunerabilities; i.e. CIFS/SMB exploits, etc. All these posts mention ports 137 & 139, but none mentioned SMB over NetBIOS .... port 445, which is just as dangerous, if not more.

So in all respects, it's not really NetBIOS that is dangerous... But the services, and applications that utilize it.