>>21240667It's actually quite simple. Officially they're not allowed to take things from other sites. They can steal information and it's impossible to prove they didn't just do the research themselves (except when they copy incorrect information, which to be fair, happens fairly often).
If they steal images, however, it's pretty easy to trace them to their original source, and since Pomf hoards all the money he makes off Bulbapedo to himself, the other site employees can't afford capture cards and therefore can't obtain their own images. So they're stuck using freely available fair-use official artwork instead, because they don't want to be caught stealing from Serebii (even though, you know, that happens all the time anyway).
Of course they've already stolen all the menu icons for the Pokémon and items (except the Mega Stones which for some reason still use the PGL artwork), so I don't know what the fuck their excuse is anymore. Basically Pomf is a lazy greedy asshole who doesn't give a shit about Pokémon, its fandom, or the quality of his own site. Big surprise there.
