Honestly no real reason other than it's the one I know and didn't want to spend any more time on finding software to write with instead of spending the time on writing
Heh I can empathise. Two of my biggest reasons for wanting to move to a static site generator are actually to have actual control over the content (in markdown files, and because WordPress and its plugins do a fair bit of processing on the raw content), and because I'm more comfortable hacking in languages that aren't PHP.
That seems to have stopped me from writing though.
> more comfortable hacking in languages that aren't PHP
Oddly enough it was the opposite of that for me. Each of the static site generators I looked at were non-PHP (which is fine but I lack the experience)
I tell you what, if someone ever had a gun to my head and said "make this Ruby software work first time without errors" they might as well just pull the trigger
Essentially it was the default option