It's all about observation bias. The SO survey wasn't representative in any conceivable way. Only active users (as already pointed out, the vast majority are passive users) who are passionate about their programming language of choice were sampled.
Most professional programmers aren't passionate about the language they use - it's a tool or a management decision, nothing to get emotional about.
The more "esoteric" or "exotic" the programming language, the more passionate its user base. Mainstream is defined by mediocracy and the average developer simply doesn't care.
In my experience, the majority of developers don't even log into StackOverflow, they purely use it as a read-only resource. I'd say even less actually fill in the survey!
Some of the most loved languages like Elixir, Clojure and Rust are fairly modern and powerful and fun to use. But they are also scary. Elixir and Clojure are functional languages, Elixir runs on a niche runtime, Clojure is a Lisp and looks foreign to people who are used to more common syntax, Rust has functional concepts baked in and is known to be hard to learn initially.
Unfamiliar + hard to learn = scary. Which leads to less overall popularity when it comes to actual jobs.
Wasn’t Rust the #1 on that poll? Yet the amount of code in Rust is practically none, and there are vanishingly few qualified/experienced Rust programmers. There’s a massive gulf between what language has the share of memes and which are used to write real code in industry.
My experience at a few places: devs try it out for hobby projects. Maybe get a POC in Elixir done at work. Ultimately the business continues to build on the existing stack. Hence, few job postings for Elixir.
Most professional programmers aren't passionate about the language they use - it's a tool or a management decision, nothing to get emotional about.
The more "esoteric" or "exotic" the programming language, the more passionate its user base. Mainstream is defined by mediocracy and the average developer simply doesn't care.