This is a use of FUD#1 (exaggeration of a weakness), but one to which Microsoft is especially vulnerable due to their long history of ignoring bug fix requests and refusing to issue bug fixes for any but the most critical bugs. It is especially helpful to talk about blue screens of death and the Navy ship left dead in the water because of NT blue-screening. Be sure to use ``talk about the blue screen of death! What if they'd been in combat?''. The goal here is to imply that Microsoft operating systems are unsuited for all mission-critical applications. The reality is, of course, that Microsoft operating systems can be used for mission-critical applications that don't need 24-hour-a-day uptime without much worry. As a simple file and print server, for example, Windows NT works just fine. It's just when you expect it to do more that problems arise.
In a way, Microsoft is a victim of their own rhetoric here. Their sales people have pushed ``NT Everywhere'' when NT clearly isn't suited yet for all purposes.