People treat WordPress like a Swiss Army Knife because they can. Why build an online directory or CRM or auction site from scratch when you can just use WordPress? It can be a bit sloppy, code-wise, but it works and you can get the job done a lot faster than it would take to do it from scratch.
Consider an online business directory. You could just build one from scratch or use some script designed for that purpose but WP simply offers more flexibility. If you decide you want a Google Map displayed in each listing, just download the relevant plugin. If you want to add oEmbed functionality (for, let's say, embedded videos), it's already built-in. If you want to do advance taxonomy queries use the Taxonomy Drill-Down plugin, etc.
Yes, it's all held together with chewing gum, but it works.
I suggested our company site be re-done using Joomla. The original site was on an ancient platform that we don't work with anymore and we kept an entire server around for it.
We spun up a cloud server with Joomla on it for production use, and a local VM for testing. We had a template created for a couple hundred bucks from some ideas our designers came up with (they can't code, so...) from an Eastern-European on a freelancing site.
Then we just let our marketing guy (also can't code) and some interns loose putting up content. It took a few weeks of their spare time and we had a great looking, functional website.
Since then, the marketing guy has installed a hundred different 'Joomla plugins of the week' and brought the site down a bunch of times, trying to make it into a blog, newsletter, signup sheet, web store...
Ugh I have been there with Joomla... my marketing guy thought he was creating Yahoo! for the 21st century but in reality he was breaking the site every 3 hours and then calling me for help.
Granted I'm not a WP expert but something like CRM seems like something that would be a different category of problem to what WP is intended to solve. It would seem like fitting a square peg into a round hole, where most of the existing functionality wouldn't even be very relevant?
My understanding is that for the more complex examples (CRM, auction site) it doesn't work particularly well. Sure you can do it but if you're having to work with Wordpress internals rather than rely on plugins that someone else has written that's when the pain hits.
I did take a look at that, and developers were still complaining about it. I also wasn't too impressed with the way that Woo went about acquiring the project to be honest.
Consider an online business directory. You could just build one from scratch or use some script designed for that purpose but WP simply offers more flexibility. If you decide you want a Google Map displayed in each listing, just download the relevant plugin. If you want to add oEmbed functionality (for, let's say, embedded videos), it's already built-in. If you want to do advance taxonomy queries use the Taxonomy Drill-Down plugin, etc.
Yes, it's all held together with chewing gum, but it works.