I don't think that's true at all. Let's set aside all the improvements Sun made to the ()nix ecosystem, which includes dtrace and filesystems and network protocols, among others.

Most servers were migrated from Sun to Linux (with minor hiccups). Sun basically set the standard for security and reliability that led to the successor instead of OS/2 or MacOS or ReactOS or whatever. Microsoft HAD to change their OS to meet the needs of the users (ANY security, more interoperability between ()nix and windows, etc).

The statement is either poorly phrased or wholly inaccurate, depending on your point of view.