What does wordpress have that something like Ghost doesn't? Working with wordpress is a real pain, it's code is not what I would want to dig into a friday afternoon. Why is wordpress still popular?
Assloads of plugins.
History.
Lowest-common-denominator hosting requirements.
I mean, I've been using WP to run my site since before Ghost was even an idea. I've got a blog, a couple of image galleries, and a couple of graphic novels. I'm using styles I designed myself for all of these, plus about a dozen plugins.
I didn't have to dig into its guts to make this stuff work. I didn't have to type a single terminal command to make it happen. I just had to upload some files via FTP, then leverage HTML/CSS and some basic PHP knowledge. And now I just type stuff into a web form, or fire up a client app on my computer (or my phone/tablet), and post whatever the hell I want to with very little friction. Those posts get mirrored to Facebook, Livejournal, Twitter, and Tumblr automatically. Comic pages get automagically collected into [chapters](http://egypt.urnash.com/rita/chapter/01/). Images get optimized, then mirrored to Wordpress' CDN. Spam comments get caught.
I'm looking at [Ghost's download page](https://ghost.org/download/) and what do I see? It requires Node. How many web hosts have Node preinstalled? Do I really have time in my busy schedule of drawing comics to install Node, get it running, and keep it up to date? My host keeps PHP up to date for me and I can get on with making the content, rather than fiddling with the blog.
I wouldn't want to dig deep into WP. Version 1 is ten years old. There's probably some horrible code from 1.0 still lying around that codebase - hell, there's probably some code left over from 2001's B2, which WP forked off of. But I don't want to dig into its code anyway. I just want to have a website that I don't have to edit by hand.
From the perspective of someone using WP to manage their content, rather than as a project in and of itself, working with it is pretty easy.
- made a paid membership system for a major trade organization, including renewable credit card payments and integration with a third-party CRM
- built an event tracking calendar, including import from Eventbrite
- a password-protected “garden” for designers to exchange wireframes and portfolio pieces with clients
It all works extremely well. Wordpress is open, well-supported and well-documented. I don't like the templating language (at all), but otherwise Wordpress works extremely well and is somehow improving with age.
Although as a developer, I agree - the code is pretty awful, even for PHP. But... small business owners, bloggers and such couldn't care less about that.
Why do I like it? It's the most productive PHP development platform that exists, hands down. With it I only have to code the unique functionality I need and not everything else.
P.S. Before anyone preaches OOP at me, realize I started teaching OOP back in 1989, and n 1991 I even wrote a book that had several chapters covering OOP.
And client familiarity, which can't be discounted (and is a two-edge sword in and of itself). I'm no fan of Wordpress and would rather use something else, but at this point there are few systems that can truly challenge it. I hope that changes soon, however.