A large number [citation needed] of Windows apps that have done this are things that most users would want to run in the background, primarily things like insta

A large number [citation needed] of Windows apps that have done this are things that most users would want to run in the background, primarily things like instant messaging clients, music players, and daemon-y programs (torrents come to mind). There's frequently a setting to configure if it truly closes or not, but it's not usually there for more mass-market targeted apps (death by settings and configuration options to support being the likely cause).