Well, what political stances do you think the people committing the hate crimes have? You're right to point out that most of the people protesting Israel's actions are not violent or necessarily antisemitic. But the post your responding to is highlighting that it IS happening. Antisemitism existed before this and it'd be foolish to act like those people wouldn't be the first people to jump on an anti-Israel political movement. So if you're interested in keeping the heart of this political movement untainted by antisemitism, then you'd do well to acknowledge its presence.