SPOILERS ALERT
SPOILERS - watch the movie first before replying.
Besides the OBVIOUSNESS of the de-facto wrongness and outright immorality of mass murder, why would simply closing down of one's favourite SHOP drive someone mad enough to murder people like that, as we see in this (although very good nonetheless) movie?
Why would someone be either so upset or driven mad by the closing down of one's (however favourite and dearly beloved) SHOP to commit brutal mass murders of its employees and staff etc like that?
I have forgiven people and not been driven to kill for often more serious and personal stuff than that.
Thanks.