And as we can see, the knife or the gigas sword had no relation to the event. They were just added to make the event rewards dont look so empty. Not everyone owns a plot and not everyone is interested in housing decoration (lets be honest here, nobody cares for your plot except your friends maybe)
Starlight event was not brilliant, but it was a helmet for every playable character. If we remove the sword and knife, well furniture only would of been pretty lame for valentines event.