Comment by stabbles

I noticed the same https://news.ycombinator.com/item?id=47940213. My working hypothesis is that, given that a filter was always required (prs and issues are likely rows in the same database with a bool property to distinguish them), someone thought it'd be good to use the search API uniformly. But search is on the derivative of the underlying data, in contrast to the specific APIs for listing issues and prs.