NI Certification is an important milestone on the path to LabVIEW enlightenment (which is more of a journey than a destination). If someone thinks she's good at LabVIEW and she hasn't taken any courses or obtained NI certification, then chances are she's not as good as she think's she is and she probably doesn't have the experience that our organization is looking for. (I'm also responsible for hiring LabVIEW developers.) A certification requirement for hiring certainly makes for a good filtering criterion (and you can't have too many). At our organization, we require that every LabVIEW developer be on a professional path to become a Certified LabVIEW Architect.
Bottom line, certification is an absolute must for anyone serious about calling himself a LabVIEW expert -- if only to understand the process and expose him to a variety of concepts. Certainly, I gained a lot by obtaining my certification (I am a CLA, and have previously held my instructor certification) -- I learned about areas of LabVIEW that I was weak in, and I subsequently strengthened those areas.
Cheers,
PS - please don't compare LabVIEW to IT (I can say this without getting in trouble because our company doesn't have an IT dept.)