Certainly. But I think this is missing the point: the argument isn't that employment protections are good because they're widespread; the argument is that employment protections are good and their wide-spreadness is a response to a perceived need (cf. "not sure this is something that needs fixing").

The positive argument is that it's already a fixture and an agreed-upon solution in most of the developed world. The normative argument, i.e. that it's good, is in the next two paragraphs.