Some people believe that PHP is a suitable introductory language. However, PHP has several major problems: lack of good abstraction mechanisms, many inconsistencies, many functions to do the same thing, and many nuances to its use. People who learn PHP right away, tend to write very bad (and sometimes very dangerous) code in it, and are not well-aware of its pitfalls.
PHP is a fine language for the web and for other uses, especially because its implementation makes deployment of some large-scale web applications easier. However, the other languages in the so-called “dynamic”, “agile”, or “scripting” class of languages are not harder to learn, and less problematic. So they should be taught first instead.