(Not sure about devs coming with cereal boxes just yet, btw... The want ads I see still ask for "PHP Coder" and offer six figure salaries for good ones)
PHP is installed on just about every server on the planet and a lot of really good companies use PHP simply because it’s so easy to get developers who know PHP. The other benefit to PHP is that it’s so simple and ridiculous that any programmer who doesn’t know PHP could master the basics in a day and be building pretty decent applications within a week or two. So, PHP certainly makes good financial sense all around.
I suggest he not present himself as having a skill which there are millions of alternatives for and which can be mastered in two days.
Instead, I would focus more on him as a package deal of domain expertise, soft skills, engineering expertise, and programming ability (including PHP) which has previously achieved successes for businesses such as brag brag brag focusing on business benefits and is ready to pitch pitch pitch focusing on business benefits for you.
(I don't mean to be argumentative, I think it's a question many developers wrestle with) When I wrote "he", I meant the fictional guy saying "I'm a PHP coder". Obviously it would be better and more true to say something like "software developer" instead of locking to a particular technology, but I'm not sure how he could further convey his value in a job description.
("Founder" is actually a good example - it can apply to Steve Jobs as well as a lot of HN users, the value each is creating is wildly different)
(Not sure about devs coming with cereal boxes just yet, btw... The want ads I see still ask for "PHP Coder" and offer six figure salaries for good ones)