One thing that I can see right away that I like is working with themes. Other comments point out the WP bloat. I don't care about bloat as long as the software is easy to install and generally stays out of my way after that (the bloat stays hidden) but one area Wordpress can get to be a bit messy looking is the themes.

If Ghost is easy to theme and the templates easier to read / build / maintain then that's a big plus for me. I may not want to touch any code on the thing, but I would certainly want to do work on the templates.