Don't worry about his comment, I watch all kinds of media 1080P or even less and they look amazing on the 1440P resolution. They look much better.
It's impossible to do better than 1:1 pixel mapping between source and monitor. A 720p frame looks worse on a 1080p display than on a 720p display because the 1080p display has to interpolate it 3:2. The same thing happens for a 1080p frame on a 1440p monitor (with a 4:3 ratio).