So it sounds like you're going with the Gartner definition. I think your frist sentence pretty much states its case without weasel words or smoke and mirrors. I'm not so sure that the rest that you include are part of the definition (that is, form a test that the software would have to pass) so much as state the likely consequences.
From that definition, "enterprise softwware" would either have to be this huge, monolithic system fully provided by one vendor, or all of the parts of a cobbled together system. From that, perl could be part of an enterprise software system, but it not itself.
I guess that makes sense.
