Throughout my time developing a competitor to Discourse, I've found that opinions are generally split 50-50 for and against pagination.
You can't really pick one method without alienating the other, but it is possible to allow the end user to choose.
Part of the hate is that IS is associated with endless scrolling. It needn't be that way if appropriate navigational tools are also implemented alongside an IS setup.
The issue with discourse is it isn’t infinite scroll. They break up the timeline into the right side and if you have an exceptionally long timeline it will skip time periods thinking you just want the original post and the new stuff.
It makes it difficult to follow the conversations.
This is correct. A problem with a sensible solution. When you scroll through NodeBB your address bar updates with the context of where you are. Copying that address will return you to where you were.
Likewise each post has a permalink in the timestamp. It will also return you to that post.