I hate this, "It's never enough" shit. Powerpuff Girls already pushed the limits because it was a girl superhero show that all audiences liked, which was a fucking rarity. But we can't stop there, we also gotta make sure we have diversity in those ranks so every kid has a same-colored role model to look up to.
What about the poor Asian kids who don't have their own Powerpuff Girl? Or the poor Spanish girls? You start saying it's necessary to keep adding to the point in order for ___ to look up to them, you get a fucking meddled mess. How about rather than adding to the pot, people just make new shows. Like Static Shock for instance. Or even fucking Jackie Chan Adventures which gave us two Asian characters (Jade and Jackie) who were basically a comical Batman and Robin. If you want a crew with diversity, then you can make a new show where that's the point: such as Xiaolin Showdown did.
At least back in the day, Warner Brothers Animation had the right idea. Now everyone just wants a fucking OC recolor, stick them in one episode and call it a day. Then remove them when the trend dies down.