Users want positive experiences, and devs want to build those positive experiences. Look at some of the most popular websites out there: Youtube, Spotify, Amazon, Reddit - they're built on interaction. You're not just reading a post on reddit, you're upvoting it and influencing the front page.
This had traditionally happened through POST/GET requests and having all the logic server-side. Yes it's possible to build interaction without Javascript, but it's not a great effect. Imagine if you had to wait for a page load every time you voted on a post on reddit.
Now extend that to modern webapps. Take Google's Voice Memos demo[1]. It loads instantly. It supports any device. You can even add it to your homescreen and you won't be able to tell it from a native app. Everything about it just works. Why would a user not want such an experience?
Javascript interaction is the natural evolution of the web. If it wasn't JS it would have been something else. This growth has been driven by users, devs, and browser vendors alike. There's nothing "arrogant" about it.
[1] https://voice-memos.appspot.com/
