If the Daily Mail is the best source, the Daily Mail is the best source and HN should have it on the front page regardless of its reputation. A similar recent case was https://news.ycombinator.com/item?id=10131399.
Not that this should necessarily be HN policy, but I think I'm probably not the only person who would prefer to read it from a marginally worse source than give page views to the Daily Mail.
On the other hand, getting visitors from HN wouldn't necessarily increase any revenue for them as being the nerds that we are, I doubt that many of us use a browser without an ad blocker ;)
