The reason why I use a mac is because everything I build is deployed on Linux. Coding on a WIndows laptop means I wouldn't be able to compile anything, and coding on an Ubuntu laptop...well...I still like having a first world OS experience.
On windows Just use an X server or run Hyperv and run VM's
OSX is a fantastic development machine. Most developers use it. It completely fits all my needs and is provided for me by employer so that I can be happy and productive and effective. Which, as you remember, was the original criticism. That Amazon DOESN'T do that.
Also I spent a good deal of time building carrier grade software for major telco's (using map reduce I might add).
Serious developers develop on Identical hardware to the live system and I mean identical as in came of the line in the same batch.
Its all about removing risk