I'm fine shooting down hostile fighter jets the second they cross into sovereign airspace, and not a moment sooner.
the Soviets used to fly fighters close to Western airspace to probe our defenses. we'd intercept, and if they crossed over we'd take them down. this is nothing new.
it also keeps defensive forces sharp, by giving them practice, and strengthens cohesion by highlighting the shared threat NATO protects its members from.
the Soviets did this for decades. it's still part of their military doctrine, I guess. though it seems counterproductive to me.