These are my headcanon explanations.
Bug > Dark: Many insects are nocturnal and are thus more active in the dark.
I thought that too at first, but many insects aren't. there are lots of ~all kinds~ of animals that are nocturnal, not just insects. idk my headcanon is 'because parasites maybe???' but even then that's pretty silly.
hopeandjoy said:
All of Psychic's weaknesses (except Steel) are psychological stuff. (Fear of Bug(s), Dark moves being under handed, Ghosts being freaky.)
psychic isn't weak to steel, steel resists psychic.
Pinkamena said:
uv, they're not the ~same thing~. Rocks are thinks you chuck at birds and bugs, and Ground is the thing we walk on, unless you are Charlie Sheen and all the drugs you take causes you to walk on air.
... what the hell do you think the ground is made from? o.o sand is variable depending on where you get it from, but it's commonly broken down rocks and shell fragments at beaches; volcanic sand is made... from broken down rocks and minerals; dirt is broken down rocks and organic matter. 'the thing we walk on', or the lithosphere, is
made from rock. Groudon, who represents the lithosphere, is a ground-type. Conceptually, the two types are muddled. I get they're not the exact same thing, but they're similar enough that it seems odd to separate them conceptually. Most ground type pokemon are based on different types of sand based on what biome you find it in (desert, muddy lakes, 'underground'), and initially there weren't any pure rock types. It kinda feels like they added ground or rock as an afterthought to build up the type chart. I can get the difference between water and ice as types, because the difference between water and ice in cultural consciousness is pretty massive. They do different things for us and have different associated legends. Rock and ground are more or less grouped together, unless you're talking gemstones, which is oddly only used as a motif in pokemon pretty occasionally (and then you have lots of pokemon that do have gemstones on them, like sableye and golduck and persian, but aren't rock or ground types).
I mean it seems like it would be way more consistent to just chuck them all together into an 'earth' type or something, but whatever.
edit: even the fossils are inconsistent; all fossil pokemon are rock-types, despite the fact that Aerodactyl, while generated from a fossil, is not actually generated from a rock. It's regenerated from Old Amber, which is suggested to have a blood-sucking insect inside containing Aerodactyl DNA, a la Jurassic Park. Idk if this was an oversight by Game Freak, or if prehistoric = rock in the pokemon world (which doesn't make any sense). And then all the fossils pokemon are primarily rock type and have a secondary type (like rock/flying for archen), except for tirtourga/carracosta, which are water/rock.