There are a lot of discussions about the pro/con of pagination vs infinite scrolling on the internet.
You may dislike the infinite scrolling, but since Discourse’s navigation was built around it, it works very well thanks to the timeline to the right, the fact that the browser remembers which post you were at when you left the thread when you come back later, etc… Also, some people won’t like it until they give it a bit of time to give it a try.
Also, I’ve migrated 3 forums from old forums with paginations to Discourse. The extremely rare complaints about the lack of pagination quickly vanished. People ended by liking it.