The stabber is a loser and his actions should be denounced by the Muslim community. That guy who got stabbed isn’t responsible for the actions of politicians in a different country.
Every culture has bad actors and good actors. People should remember what it’s like to be held responsible or accountable for the actions of someone else. All cultures have done this to each other at some point.
Blaming random civilians for the big things which someone thinks are wrong in the world is an inherently wrong and dangerous thing to do. The police should also investigate if this stabber might not have other motives, like did someone incite this person to start a conflict in this community?