Why does Electrocute have such high stat scaling, all things considered?

Not only does the rune deal more base damage than Thunderlord's for the first 17 levels, it also scales better AND deals adaptive damage (which just makes it scale even better on ADs and snowball harder due to benefiting from lethality).

40% Bonus AD doesn't sound like that big a leap over TLD's 30%, but again, Electrocute is physical damage with that bonus AD and thus uses your lethality too. So buying that Youmuu's/Duskblade is actually a not-too-insignificant boost to Electrocute's damage (22 additional damage plus lethality). Yes, it does mean the rune gets impeded by armor/Seeker's Armguard, but forcing the enemy to buy Seeker's is an advantage in and of itself because the item gives no mana or CDR.

As for mages, Electrocute has 25% AP scaling to TLD's 10%. That's a 150% increase in scaling. Something something LeBlanc.

I'm just saying words at this point. Just seems like Electrocute's scalings are a bit high.