I would say targetting individuals when trying to upset them should be policed, however this is not about individuals but a large group.

If you, say, bankrupted someone's company so they had to sell all their possessions and then went up to them and burned the Quran they got from their now dead father as a present as a child or that had been in their family for generations right in front of them, that would be something that should be illegal as targetted harassment.

However here we are talking about criticism of a religion by burning a symbol of the religion, not one particular person's possessions.