PHP didn't succeed because of the "language" part. It succeeded because it was limited and focussed to just being a tool to write small web-apps in a short time.
It did one thing and did it better than anything else of the same era (I built CGI apps in C, Perl and Python before discovering PHP).
It was just files, that you ftp-d in and it just worked.
99% of the friction is in writing the first thousand lines of code and PHP meant that nearly all of those lines was business logic, not unescaping POST data or parsing GET parameters.
PHP doesn't remove your ability to think clearly. It is true that it does not provide helpful additions for algorithmic work, but it does not put challenges in your way when writing web-apps. And yet, it does not force you into too much magic about how it works - just enough abstraction for a messy coder.