I thought of a few more reasons.
>Remakes started in Gen 3, why would it be retro if the modern remakes started during it>Ash lost his classic outfit during the Gen 3 anime>Pokemania was pretty much over by this point>>48448851I bet you think the Gamecube, PS2, and Wii are retro too... Just because it was 20 years ago does not classify it as retro.
Furthermore, if Gen III isn't the start of modern Pokemon, when do you consider it?