The word itself means "can't understand" in outdated speech.
The context is usually when something that got no business with the characters' conflict and do nothing wrong (e.g: glasses, can, bystander, objects, random mob in Attack on Titan) got crushed or killed for reason they got nothing to do with.
Hence: I can't understand why I deserve getting killed like this (in a more justifiable meaning than the usual yukkuri babbling)
WHRRryyy you do a cruel thing like this to Reimu?!You are planning to do cruel things to Reimu, right?!Yuyu?The endYyuhyuhuyuh...*SPLOFT**NHACK*PUUUUUFF!Reimu will protect her cute little ones!