The runner wasn't blasted for the PR.
The poster was blasted for getting excited by a time that was fairly mediocre compared to the runner's other PR's..
Actually i think you're wrong. He was excited about Leer setting a pr, not the time by itself. If someone is a fan of Leer, there's nothing wrong with getting excited about his improvements. It was worthy enough to post on letsrun.
The fact that it's mediocre compared to someone else's PR is a moot point.