I'd like to think a little differently on this. While it is true that many of the users on this site will always say 'perl is the best language no matter what you need to do', I think you'd be surprised at the number of people who will give their honest opinion if they are well-educated in both Perl and the language in question (in this case, php).
Dare I say it? There are those few times when perhaps Perl is not the best option available for the job. And those who know the true differences between languages, as well as the strengths and weaknesses between them, are not going to lie about which option might be the most suitable.
Therefore, I think it is perfectly valid for a person to ask if maybe a certain task would be easily accomplished with another language. Remember: just because someone frequently visits perlmonks doesn't mean that they don't know anything else besides perl. I can't find it, but the perlmonks FAQ mentions somewhere that off-topic questions are generally well-accepted here because of the fact that Perl isn't the only thing we here know about :)
>> Could not shut down computer:
>> Microsoft is logged in remotely.