Weeeeell, I don't think that it is.
Christ knows I understand the importance of a shared lexicon, but if I can explain what I'm doing, coherently, in plain English (and I can), then I question the importance of buzzwords like "agile development" and "LAMP". (Nebulous fucking horseshit like "the cloud", though, IS a separate issue.) A convenient shared shorthand is a good thing to have -- it's also something you can learn on the job.
The point, I think, is that interview preparation resembles nothing so much as last-minute cramming for a vocab test, and is just about as accurate a gauge of actual knowledge and understanding of the material.
Stross had a post not long ago about the importance of editors being a lot more than simply correcting typos. A commenter said something along the lines of "But if you don't know what the phrase 'Oxford comma' means then you shouldn't be looking for a job as an editor."
While I think it's probably a good idea to know vocabulary like "Oxford comma", I am viscerally opposed to the notion that it should be make-or-break. If you're looking for a job as an editor I think it's pretty much a certainty that you're familiar with the question of whether to put a comma before "and", and that matters a fuck of a lot more than whether you know what it's called.