Many good and well-designed languages are older than PHP (Scheme is from 1975!), so that cannot be the cause of PHP's poor design.
Rasmus Lerdoff actually gave a great talk on why he created PHP and how it sort of accidentally turned into a programming language:
https://www.youtube.com/watch?v=nmD1Q4FsXCc
Those old tools still worked, just not as well as modern versions.