I've been to JSConf EU a couple of times and it's certainly not a JavaScript conference "about building web sites".
Aside from the non-technical talks there were talks like
* how concurrency works in modern JS engines
* a talk about the upcoming BigInt type
* how fingerprinting attacks can circumvent privacy measures
* HTTP/2 Push
* a look at upcoming language proposals
* a retrospective on the JS build tool for React Native
* a talk about versioning
* experimental time travel debugging support in Firefox
* a talk about error handling
* a talk about module systems in JS
Etc etc.
Sure, many talks are either about general web technologies or about new APIs of the web platform, but there is usually also significantly overlap with backend or native mobile and IOT.
When I worked with Python I also went to meetups and followed conferences which always had a wide range of talks from web frameworks to automation, data science and system administration.
Likewise at a Ruby conference I'd also expect talks about tools like Chef or Puppet, which are only tangentially related to web development specifically.
So I don't think your portrayal of conferences is fair at all. "Why aren't there ${language} conferences?" seems like a very sound question, even if ${language} is used in a wide range of industries for very different purposes.
Aside from the non-technical talks there were talks like
* how concurrency works in modern JS engines
* a talk about the upcoming BigInt type
* how fingerprinting attacks can circumvent privacy measures
* HTTP/2 Push
* a look at upcoming language proposals
* a retrospective on the JS build tool for React Native
* a talk about versioning
* experimental time travel debugging support in Firefox
* a talk about error handling
* a talk about module systems in JS
Etc etc.
Sure, many talks are either about general web technologies or about new APIs of the web platform, but there is usually also significantly overlap with backend or native mobile and IOT.
When I worked with Python I also went to meetups and followed conferences which always had a wide range of talks from web frameworks to automation, data science and system administration.
Likewise at a Ruby conference I'd also expect talks about tools like Chef or Puppet, which are only tangentially related to web development specifically.
So I don't think your portrayal of conferences is fair at all. "Why aren't there ${language} conferences?" seems like a very sound question, even if ${language} is used in a wide range of industries for very different purposes.