"just getting a working PHP environment up and running was complicated enough" Hah, that was one of the biggest strength of PHP stack - it was not complicated;

"just getting a working PHP environment up and running was complicated enough" Hah, that was one of the biggest strength of PHP stack - it was not complicated; on you MS Windows machine it was enough to install some wammp/xammp, etc. PHP/MySQL/Apache bundle, open editor, put in the first line <? and start coding. On production, typically some shared hosting (cheap! Another said stack advantage) this was already installed, so it was sufficient to FTP files over there and be done (one more advantage). There was no other comparable stack in terms on simplicity and being able to do something quickly. I believe there is none today, only PHP stack matured, so there are frameworks, etc. Yes, there were security concerns, but still much less comparing to its server-side predecessor CGI scripts (better known today as AWS lambdas or "serverless").