Should have stopped who?
We simply don't have the means to determine who is a terrorist and who is fleeing the very same terrorists responoble for acts like this.
What ha's happened in Munich pales to insignificance compared to what happens I Syria and fully justifies why Europe should be a cepting as many refugees as possible. And decent human sold be doing their best to accondate fleeing refugees escaping such atrocities an standing up against terrorim.
Blaming migrants is exactly what the terrorists want. The terrorists win when someone brandishes refugees or Muslims as terrorists.
Why should Europe accept them though, what about all those oil rich Muslim countries? How many have the Saudi's accepted? What about Iran, Qatar, UAE, Pakistan, India? Oh right, they don't want to live there because Europe is rich