Not to beat a dead horse, but the whole “PPGs and RRBs are siblings” thing has always felt more like an observational fan theory than an actual confirmed fact. There’s definitely an argument for it, and I understand why some people like the theory (hell I vibe with it✌️), but at the end of the day it depends on whether or not you buy into that interpretation. The show itself never really confirms it.
That reminds me a bit of the whole thing with Kagamine Rin and Len from Vocaloid….
A lot of people see Rin and Len and immediately assume they’re twins because of how similar they look, even though they aren’t canonically siblings. Some people ship them, some people don’t, and both reactions are valid. Even if something isn’t technically incestuous, people can still find it uncomfortable, and that’s their right.
A lot of this comes down to personal preference in character design. Personally, I’ve always found contrasting designs more interesting than matching ones. I’m talking height differences, different color palettes, different silhouettes, different personalities! characters who visually and narratively bounce off each other.
Part of the reason for that is that modern audiences tend to place a much bigger emphasis on visual individuality than older cartoons did. Nowadays, it’s practically a meme that cartoon couples look like siblings because they share the same face shape, body type, or overall design. That’s one reason designs like Mickey and Minnie can look a little strange to modern viewers. They’re products of a different era of animation, where simplifying characters and reusing similar visual language was common practice. It’s less a flaw in the designs themselves and more a byproduct of animation standards from the 192 was and early cartoon era. It was so common place. It never stopped and still standard practice for animators all the way up to the 90s and 2000s.
The Powerpuff Girls and Rowdyruff Boys don’t really have that kind of contrast because they’re intentionally designed as counterparts. For some people, that’s the appeal. For others, it’s exactly why they look elsewhere or end up redesigning the characters from the ground up. There aren’t actually that many options once you get into the whole “they need to be with their own kind” debate, which has always made me a little uncomfortable anyway.
(I know that was a huge tangent, but I thought I would bring it up because I just know someone will mention it in the comment somewhere)
I also see people bring up the fact that the boys were revived by HIM, but I’ve never really found that argument convincing either. HIM didn’t create entirely new characters; he resurrected characters that already existed. They’re still the same Rowdyruff Boys, just brought back after being defeated. Whether that changes how people interpret their connection to the girls is up to them, but I’ve always seen it as a revival rather than the creation of a new set of characters.
As for people shipping the girls with the Powerpunk Girls, I’ve always seen that as falling into the same category as clone ships, alternate universe ships, evil counterpart ships, and all the other weird fandom stuff that have existed forever. It’s basically like that one question you think about while laying in your bed at night of, “If you could clone yourself, would you date them?” It’s not really something I take all that seriously.
I don’t personally ship it, but I also don’t feel nearly as strongly about it as some people do. I can understand why someone looking for a lesbian alternative to other ships might gravitate toward it. There are aspects of the dynamic that people find interesting even if they don’t like the more popular counterpart….
Really, this whole discussion exists in a gray area where people can hide behind what’s technically true while still making others uncomfortable. That’s why I think most of these debates ultimately come down to interpretation rather than objective right or wrong.
At the end of the day, fandom has been shipping alternate versions of characters, clones, counterparts, and mirror-universe doubles or even just literally the character themselves for years. It’s not exactly a new phenomenon. We all remember what happened with the Onceler.