You're claiming that B2W2 had 'much' to do with regards to how it is now. Yet you list a series of causes that aren't any of my issues with Best Wishes. I have a problem with the league, not Cameron and Riolu per sé. I have issues with the spacing between gyms, and them honestly being subpar, so Roxie, Marlon and Cheren featuring honestly didn't really feel like all that much of an issue either.
You're taking 'breeding' far too literal. Check what I just wrote. Breeding, in the animé sense of the word, has very little to do with teaching new moves, and hatching new eggs. It had everything to do with taking care of pokemon, to the extent of them being able to perform at the best of their performance level. If you knew anything about Brock, then you'd recognize that all he did had to do with his goal, be it breeding, or becoming a doctor, and who he is. Brock had to take care of his siblings, because his parents were not there. Just as well, Brock preferred to take care of his pokemon then battling with them, and THAT'S what his goal became. Which is why he immediately left the Pewter Gym when a possibility (the return of his father) arose. He left, to become better at taking care of his pokemon, coining the term as 'breeding', but better understood as grooming, or care taker. Which is what Brock did in quite a few episodes. Yes, the Vulpix episode was one of the few which directly addressed 'Breeding', but there have been multiple episodes that showcase Brock as the one guy of the group that lets pokemon achieve their maximum potential.
Brock stepped in every single time when a Pokemon got sick. Look at the Pachirisu Fever episode. He would be the Laura Dern in Jurassic Park if he found that Triceratops. He would stick his arm - elbow deep - into the manure in order to find why a pokemon was sick, in order to make it better. BEFORE HE EVEN DECIDED THAT TO BE A DOCTOR, AND REALIZED WHAT HE ACTUALLY WOULD END UP AS.