No, it's the exact opposite of the point you are making. I'm saying that they probably would have struggled to destroy it even if they'd tried to. Indeed, they'd probably have managed it by aiming elsewhere, such was the general accuracy of bombing.
Also, one of the biggest lessons from World War II that should have been picked up at the time but apparently wasn't (for, I think, cynical reasons) was that bombing a country into oblivion tends to have a surprisingly small effect on morale. The belief that sustained, heavy, civilian-targeted bombing would destroy morale was based on manipulated data and then used to justify the Allied Bombing campaigns later in the war that destroyed e.g. Dresden and other places, for major loss of life with minor military impact.
I'm sure that the effect of destroying Nelson's column would have been only to strengthen the resolve of the people to stand up to the aggressors, as was the case when we returned the favour later in the war,