I would ask what constitutes a "proper programming language."

I learned algorithms using 1970's BASIC and 1960's FORTRAN. Talk about limited languages. Neither had support for data structures other than arrays and scalars, control structures were limited to if-then, for loops and goto.* We could compute determinants of matrices and bubblesort with the best of 'em. It just took a bit to write.

Perl contains the features right out of the box to implement algorithms: control structures, data structures, recursion, objects. Most of these have been enhanced via CPAN. My own experience and imagination are limited; I wonder what sort of algorithms your colleague has in mind that cannot be implemented in Perl. Especially those relevant to a beginner.

*But we were grateful to have them!