I've had that first impression last year, when i heard about discourse but later found many communities liking it. In general, that is what many webmasters would be seeking, building great communities :0)
I know several sites which runs it using a vps not even dedicated, but true you would need to have ads to generate your server fees, and i think now days that is not as hard as 7 years ago. Of course discourse is not for everyone, just for those who sees that it will actually work for them by creating a decent to a big community.
Endless scrolling is not fun when i first looked at it but later I found that this wasn't the point for many communities, the point is to keep an ongoing different active discussions.
https://meta.discourse.org/t/beginne...g-docker/12156
It is been a year since they launch it, so i would say give them more time to implement a strong search function and may be a pagination option for those who don't like to scroll up/down, that shouldn't be an issue. But then Twitter is all about scrolling up and down, there isn't pagination, and it is very popular. Same with G+ and FB, we have to scroll up and down for new feeds.