Comment by hunterpayne

No web dev I have ever met could use Prolog well. I think your statement about web devs being polyglots is based upon the fact that web devs chase every industry fad. I think that has a lot to do with the nature and economics of web dev work (I'm not blaming the web devs for this). I mean the best way to succeed as a webdev is to write your own version of a framework that does the same thing as the last 10 frameworks but with better buzzword marketing.

Generally speaking, all the languages they know are pretty similar to each other. Bolting on lambdas isn't the same as doing pure FP. Also, anytime a problem comes up where you would actually need a weird language based upon different math, those problems will be assigned to some other kind of developer (probably one with a really strong CS background).