According to Tony Bibbs, PHP's real problem is itself.:
So what do I mean when I say PHP's problem is PHP itself? [...] One word. Sustainability.
He suggests that, while PHP has made a big splash in the areas it's hit, it is still tripping over its own feet. PHP, the language, can meet the needs of just about any sort of web development that might come down the line, but when good PHP developers are so hard to find, why should any organization bother with working it into their technology stack?
Comments on the article responds to the "chicken and egg situation" Tony has presented and how things like user groups can help stoke the fires of PHP's presence in not only the budding web developers but also in the professionals looking to expand their horizons.