NT breaks with sufficient frequency that it makes us seriously look at the level of support resources required to simply provide decent customer support. Inevitably, the Technet article, if one exists, will say 'Microsoft is researching the problem'. That provides little solace to those trying to get the job done. NT is incapable of running in a 24x7 fashion, as is commonplace among more traditional Enterprise systems. In any active business, it is a fallacy to believe that machine configurations remain stable.
Growth is inevitable.
To add further insult, the fixes are often tied to the service packs in perhaps even a different release. This leads to my second point wherein I would argue that Microsoft has no sense of enterprise software and support paradigms. They assume that we will slavishly migrate to the latest version of every little bit of software as it comes available, which is exactly what enterprise oriented data processing does not do. Due to the need for the utmost in reliability, software will often age considerably before the need to upgrade outweighs the risks of a system failure. Vendors of enterprise software realize this and tend to provide the maximum amount of continuous availability migration aids for such ventures.