I don't know why you wanna turn it off. It's good!
It's just your personal opinion based on what you are expecting from the game, not an absolute property of weapon flashing. I don't want weapons/flag to flash, because it doesn't fit the aesthetics of sacrificial war in trenches, and realistic mode.
Might be a good idea to suggest a way to reduce the flashing/blinking duration too... :/
IMO flash duration should be customisable too...