As mentioned by others, the emphasis in the name is on the fact that it's a Wind...

wolfgang42 on July 18, 2017 | parent | context | favorite | on: How Google Wants to Rewire the Internet

As mentioned by others, the emphasis in the name is on the fact that it's a Windows Subsystem. The historical precedent for this name is "Windows Services for UNIX", which similarly provided a Unix environment on Windows NT.