Because this is HN. Expect some guidelines-lawyer to cite some section that was technically breached by that informative reply.
That's the problem.
When facts/information doesn't align with one's agenda, some people have a terrible habit of trying to have it hidden/banned/removed/etc.
You would think in hackernews of all places, we'd upvote the comment to see exactly what trump wrote so that we can decide for ourselves when it was "glorifying violence". Sadly, many here don't want that to happen.
Funny how personal bias can twist perceptions.