Why aren't they included in the shotgun surgeon perk?

Since they are sort off shot guns.

Is there a reason they shouldn't?

Energy weapons, really the Ammo, do not have spread so would not need this Perk.

i would assume that since they are energy they cannot be affected in ways that shotgun shells/slugs can. The shots dont have "weight" to them so "stay back" wouldnt work and energy doesnt particularly seem to have any chance of AP in any form (ie Shoty Surgeon) so i would assume that this is why...IMO