[djsumdog]

It's type system and automatic casting/comparing is a nightmare.

Although there are namespaces now, the idea of everything being in the global scope was insane (and still even with namespaces, much is still in the global scope).

mysql_real_escape_string

There are no type-safe comparisons for greater or less then (You have ===, but no <== or >==).

This article: https://eev.ee/blog/2012/04/09/php-a-fractal-of-bad-design/

This subreddit: https://reddit.com/r/lolphp

The number of bugs that are closed as not-a-bug/wontfix.

I'm not sure how much of this has been fixed, but I've moved on to different languages and career choices and don't really want to look back that way.