The old "we want to be able to call the vendor" line is standard CTO bull for "I don't understand Perl and thus I fear it." Anyone who has actually called a vendor for support, and has compared the speed and quality of the response to what you get for free on the dozens of Perl support sites, lists, newsgroups, and IRC channels knows that vendor support is a joke.

The C language has no support, but C compilers do. SQL has no support, but Oracle does. I don't think you'll win the argument that way.

Demonstrating the quality of support Perl has and the support available for purchase from ActiveState would be enough to convince any reasonable person. However, support is almost certainly an excuse, rather than the real reason, so winning that argument may be useless. Of course, if you can get your employer to give some money to ActiveState, by all means do it. ActiveState pays people to improve Perl for us, so it would be nice to keep them in business.