Personally, I wouldn't spend time setting smooth scrolling up, not to mention implementing it. I doesn't seem to have much impact to my reading. The scrollable things I use is the browser and a PDF reader. Firefox scrolls smoothly, while the PDF reader doesn't, but my experience reading with both is about the same. So I sympathize with devs who put their time into solving other problems.

I'd be interested in hearing from people who feel the opposite.

Application devs shouldn't have to implement smooth scrolling. The DE should, and make it toggleable on a per-application basis.

I disable smooth scrolling everywhere. I find it slow and distracting.