You are completely incorrect.
Whether Reshiram and Zekrom are inspired upon Yu-Gi-Oh! monsters is nothing but talk since the majority of people cannot pin-point specific monsters aside from the flawed BEWD and REBD argument, but saying that "Pokémon cannot derive inspiration from other franchises because they do not generate as much money" is just so incredibly ridiculous.
So many Pokémon are based upon outside sources. Take Yanmega, Crawdaunt, Rhydon and Nidoking for example. These Pokémon without a doubt bear uncanny similarities with classic kaijus Meganulon, Ebirah, Moguera and Baragon respectively. Do Toho Studios generate as much income as The Pokémon Company? No.
The Pachirisu comparison is incorrect as well. The point of a good design is to stand out, be gracious, simple and not convoluted. Can you tell at first glance and with few words what the majority of Generation 4's legendaries, Gallade, Lickilicky, Luvdisc and Swalot are supposed to be? These are the epitome of terrible designing. Pachirisu does not have a good design because it does not stand out from a much superior design which is Pikachu (same as Minum and Plusle).
Pokémon is changing, yes. But many of these new designs leave so much to be desired. Scientists have identified more than 2 million species and an endless amount of creative combinations yet they feel the need to create these potpourri creatures.