At least in my experience, the early years of PHP was lacking more enterprisey users; back then there was a small revolution when RoR came out and introduced the MVC pattern to a lot of (web) developers, who didn't have as opinionated a pattern / architecture up until then.

During that same period, there were a lot of mediocre tutorials and documentation online, including on the PHP website itself which allowed people in comments to post code examples, but as far as I know there wasn't a lot of moderation on those.

And finally, a lot of people ended up writing their own frameworks and the like, because they could. But also because there weren't any or not many good and widely adopted frameworks out there, that came later with first Zend Framework and then Laravel, the latter being the de-facto standard nowadays.