Maybe one is all they have.
The single shot attack is nothing but suicide.
So is flying a plane into a tall building.
In the case where we have groups being fed information by our old, cold war enemies, who have little to lose and paradise to gain, who might be nuked to ash in return, we still will have been spanked, to the benefit of those same old cold war enemies who would gladly take advantage of the mayhem to consolidate their power in other regions, if they did not decide to mess with us at home.
Hardening critical systems or even back-ups could conceiveably be done as part of upgrades to the power grid which should be done anyway.
If they have only one then they would be suicidal and their families should be concerned enough to turn them in so they don’t all get fried to the fifth relation.
WTC911 could have had a nuclear response, but after a couple days it would no longer have been anything but cold. In the heat of the moment the birds could have flown and those who would have been on the other end know that. Most of their leaders were quick to commiserate because they knew.
And, hardening of electronics has been a very active program since Sputnik, which happened to be the beginning of semiconductor electronics as well as ICBMs.