Please tell me more about these PHP projects, if you have the data available to you.
* Did they support EOL'd versions of PHP?
* Are they legacy WordPress/Drupal/Joomla projects that haven't been updated in years?
* Are they in the "we (didn't use a framework|rolled our own framework) and used the mysql_* functions" league?
* Did they attempt to do something weird/crazy (i.e. store all session state in an encrypted cookie instead of server-side like normal, but forget to authenticate the ciphertext)?
Those are the kinds of things that I rarely find in modern PHP projects.
One thing I think Evert neglected to mention in his post: There's definitely an ecosystem problem. Incidentally, I've been working on cleaning it up on multiple fronts:
* Improving the quality of information developers will find via Google search or StackOverflow
* Writing blog posts that address security concerns e.g. https://paragonie.com/blog/2016/02/how-safely-store-password...
* Improving the security of the tools and frameworks developers use
* Working to improve the language itself (part of the reason why PHP 7's CSPRNG functions don't fail open is because a few of us were very vocal on how/why that would harm security)