Part of the reason this issue pisses me off so much is that I have a degree from one of the top CS programs in the world. I was definitely more of a theory than a systems person. And yet it still feels like a pile of unnecessary ego-stroking gibberish.
I feel comfortable saying most people who make software are less-experienced in this area than I am. When I run into this, I can at least say: "This is bullshit", and not feel the imposter syndrome of "It's just me -- I'm not smart enough for this" that I imagine most people feel.
Beyond that, functional programming is, by and large, easier than imperative programming. I love writing Scala -- It's honest about side effects, honest about concurrency, and has one of the better type checkers around. And I'm sick of seeing people try to "fence off the riffraff" by raising the barrier of entry to the Scala community.