[pbourke]

The point is that if you know one of the languages cited by the parent ("C++, Perl, and even PHP"), then you do make your life easier by working with that language rather than choosing one which you don't know.

All other things being equal, sure, choose the maximally powerful language in whichever dimension makes sense. But all other things are usually not equal.

If you are working on a project by yourself, here are some things which are more important than the characteristics of the language:

  - your knowledge of the problem domain
  - your knowledge of general software development
  - your knowledge of the limits, capabilities and ecosystem 
    of the language (aka project experience)

Also, if you're working with others, the following factors are more important than choice of language:

  - your customer's expectations (if you're shipping software to them)
  - the ability to recruit experienced individuals for your project
  - the availability of mentors / reviewers within your organization
  - the availability of secondary resources (books, FAQ, etc)

(edit: formatting)