I checked the list of paralysis inducing moves, and yeah: Lick, Body Slam, Dragon Breath, Bounce, Force Palm, Stun Spore, and the ability Effect Spore have definitely nothing to do with electricity. Tri-Attack and Freeze Shock seem logical since they do involve using electricity, even though they don't belong to this type.
It's kinda funny that you cannot paralyze an Electric Pokémon by fear (Lick) or spores but you can put a Psychic Pokémon to sleep via Hypnosis. It could have been a nice touch if they gave a slight Accuracy boost to Hypnosis while making Psychic types immune to it to compensate.
Considering Gen VII dropped Thunder Wave's accuracy (100% -> 90%) and made the speed drop from paralysis smaller (75% -> 50%) it seems like GameFreak thought Paralysis was OP and they needed some way to counter that.
I don't really do competitive so I don't know if these paralysis changes had huge impacts on the metas from Gen V -> Gen VI and Gen VI -> Gen VII (and even if I did do competitive, I probably wouldn't be able to tell because the metas had huge changes due to new mechanics introduced which could very well cover these paralysis changes).
Still, I suppose it does make some sense. Electric types are always associated with energy and of the moves that can cause paralysis:
- 1 is Tri-Attack so it's implied Electricity
- 1 only paralyzes if the user is paralyzed
- 1 only paralyze in a certain terrain
- 1 is a Partner Pikachu exclusive
- 1 is Fling with Light Ball
- 16 are Electric moves
Of the remaining 10 moves, 1 is a spore move, 1 is a G-Max move that's implied to be a spore move. The other 8 are legit normal moves.
So yeah, Electricity is by far the most common cause of paralysis. Electric Pokémon having a blanket immunity is probably easier to code and considering the association is probably OK.
You can even make a pseudo-biological explanation that they physically can't sit still unless they're sleeping because of excess energy or something like that.
And yeah I agree that electric should only be immune to electric paralysis. Just like ghost is or was (not sure of current gen changes) immune to glare because it is a normal paralysis move. Unfortunately I think it's possible that cubchoo is accurate in saying that it is easier to code a blanket immunity for a type instead of individual moves, so maybe it would have caused issues in the rest of the game if game freak tried it who knows though
Yeah, that's the thing. I forgot to mention Glare but that, and Lick, are moves existing since Gen 1 that paralyze through intimidation or fear. It was never meant to be a status condition specifically related to the Electric type, it was just about restraining the opponent's movement and speed through various means. Besides, if it was purely an Electric thing, Ground should be immune to all forms of Paralysis as well.