It was mostly made for simple scripts to embed on a website for animations and handling updates without refreshing whole page. Not to make a full portable client (browser) side app.
Hating JavaScript is mostly a meme, it's just a programming language. But its very loose syntax, fact it's often someone's first programming language to learn and how most programs written in it nowadays are a hack build on top of a hack on top a hack makes this language easy to laugh at.