I don't mind the "Aim for the Horn" thing; never did, and found the whole mockery more silly than the mocked attack itself. This is because I always treated it as Rhyhorn's horn was metallic, and thus, it acted like a lightning rod. Yeah, I know ground type Pokemon transfers that electricity to the ground, but still, the fact that they tried to make it look like Pikachu's electricity hit a part of Rhyhorn that's seemingly conductive to electricity (keyword being "seemingly") was enough not to make me complain about it as a 10 year old child. It was fascinating, even. People really need to lighten up about creative liberties and not take adaptations so seriously (even if I could somewhat understand the frustration).
Here's the thing: Pokemon lore is rarely properly explained in the anime. Sure, a lot of people assumed that people watching the Pokemon anime automatically have interest in the games as well, thus being knowledgeable of how ground type Pokemon stay grounded and become immune to electricity... Actually, wait, even the games don't explain that. It's a game created for 10 year olds (let's face it; by Sun and Moon alone, you can tell it's a game for children). Do you really think such scientific technobabble would be explained to a bunch of kids more interested in catching fictional monsters during recess? I don't think kids would care, nor should they. It's a fictional universe, and if the laws of physics were never really established to begin with, should we really assume that our own science in the real world could apply in the Pokemon world as well? If so, then there are TONS of things that are either not scientifically accurate or just plain doesn't make sense. What if the way ground type Pokemon deflect electricity is by harnessing some invisible chemical aura from their body, thus forming said "type resistance"? And maybe Rhyhorn just happens to be one unlucky guy to have a metal horn (again, it's never really established what his horn is made of in the anime or the games). We wouldn't know, because it's never been explained.
And what about dodging? People keep on complaining about moves being dodged, when they're probably just upset that the Pokemon games are so primitive that they don't even have the dodge function, unlike the real world or the anime. A lot of things in the Pokemon anime, especially in season one, were set to real world logic rather than Pokemon or video game logic, such as the ability to dodge or having to feed your Pokemon and yourself during your Pokemon journey. So I don't see why dodging, a perfectly realistic move any animal could perform, would be such a big deal when it only adds to the intensity of the battle. Let's face it - your Pokemon matches would be far lengthier and even more intense if your opponent is able to dodge or use the stadium battleground to its advantage (without terrain moves/abilities, mind you). Imagine being able to burn the battleground so that the water Pokemon becomes dehydrated. Yep, I'm of course referring to the epic Johto battle between Ash and Gary. If only we could pull that off in the games.