alt Hacker NewsThat doesn't really solve the problem. I've gotten PRs that do do an adequate job of explaining why why something should be implemented. Then I look at the code and it doesn't fully solve the problem, or it does so in a way that will obviously break something else.
In that case, isn't a sufficiently reasoned "why" a contribution in itself?
Not trying to downplay the time wasted to reject the PR, though.