1. I have never seen a framework that didn't go to great lengths to update to new changes quickly in development

2. Which means you lose resources between requests, unless you stuff them into the interpreter/httpd itself. And anyway this is only a problem for PHP, where by default everything runs in the top-level namespace, versus in separate functions.

3. That's a funny way to spin "no concurrency", but you can get that in any language by just not deploying it threaded.