There are plenty of good reasons why you might want a local Linux based web development environment even if you normally use Windows for your day to day computing.
One way or another you're actually using Linux every day.
Anyone who runs a web server with database intensive web sites and applications knows how hard it can be to tame this beast and end up with just the right MySQL configuration for your circumstances.
There are many ways to check your disk usage on Linux, but in certain settings and situations you might need to do it using the good old Linux command line utilities.
If you're running a Linux server you probably want to know when there are any issues the moment the incident happens so you can address it sooner and minimize any service outage.