I was a Python developer for about 10 years before joining a startup that works almost exclusively in Javascript. I had to swallow my pride and make the best of it. I had a huge, smug chip in my shoulder.
ES6 has made the language tolerable. Enjoyable even. It has even been a decent medium for mentoring more junior developers who haven't had any exposure to functional programming in school. I can show them combinators, functors, applicatives without all of the usual ceremony in a more pure language. For that JS has been quite nice.
However for my own projects I just use GHCJS or Bucklescript and compile down to JS. Google Closure and Webpack are fine tools for shaking out the unused code and bundling everything up.
Current Python dev here. I've found the same thing. I really didn't like Javascript prior to using ES6. Now it's fairly tolerable. I'm currently building an app with a React based front end and a Flask-based API for data exploration and QAQC.
The "where does the semi-colon go" game is really annoying, but I'm getting better at it, and ESLint will let me know when I mess up. But I do enjoy a lot of the features in ES6 that make JS (EcmaScript will never sound right to me) nicer to write.
My huge pet peeve is that it feels like it takes so much work to set up an app compared to my experience in Python. But maybe that's tooling. I do have some boiler-plate code to get things working, such as setup.py templates and YouCompleteMe for code completion, and I use VirtualEnv and Pip to manage dependencies. I guess that's basically Webpack and NPM and package.json/webpack.config in JS development.
Who knows. My issues with JS/ES might be all in my head.
I'm one of those people that just trusts ASI. Once you stop inserting them you stop noticing so much.
After introducing an ESLint configuration to my team I still can't get the semi-colon lovers to consistently insert semi-colons. I made semi-colons a warning only just to see since ASI will insert them anyway. The worst offenders are the die-hards.
I was originally a semi-colon person but that's only because I listened to a talk by Crockford once and never thought to draw my own opinion. As a Python programmer I thought semi-colons were silly already and this talk only entrenched the unfounded idea that Javascript was bad in my mind.
I use them at work because when in Rome... but in my own projects there's no need for them.
Currying is a nice effect of the fat-arrow syntax for lambdas. Currying in JS is still neutered compared to OCaml or Haskell where it's the default but it's still nice. Function composition is greatly enhanced by it. Python requires special help to do currying.
As for tooling... it's the same deal in many languages despite all of the marketing. It might feel painful to get a good development environment set up for a Javascript project but it can be equally painful to setup a Python environment if you haven't done it before (or a .Net, Java, etc, etc). I'm not a huge fan of excessive configuration. But that's what you get with programmers. We're a fickle bunch.
What Python does well though is to absorb good ideas into the implementation. Function decorators, iterators, and soon mypy; when you go with the grain, Python is a wonderful language.
ES6 has made the language tolerable. Enjoyable even. It has even been a decent medium for mentoring more junior developers who haven't had any exposure to functional programming in school. I can show them combinators, functors, applicatives without all of the usual ceremony in a more pure language. For that JS has been quite nice.
However for my own projects I just use GHCJS or Bucklescript and compile down to JS. Google Closure and Webpack are fine tools for shaking out the unused code and bundling everything up.