Ok before I start this I just wanna make sure very clear that I DO NOT HAVE ANY PROBLEM WITH PEOPLE WHO HAVE THE HEADCANON OF FUTABA AND GORO BEING SIBLINGS. I also think that for just a fan theory, it actually perfectly fits within the game's canon, and doesn't require a lot of change in the story in order for it to be canon. But these aren't my problems with the fan theory. My problem is that I feel like too many people have this headcanon just to have Futaba be friendly with Goro and to bicker with him, which isn't necessarily an issue, but it is weird to me that they believe in a theory with so many radical implications, simply so that Futaba won't despise Goro for killing her mother, because you can easily have both be friends with another explanation. Or hell maybe no explanation because we're talking about fanfics, you don't need to put as much effort into them as something that will be sold for real money. Also if you believe that headcanon while also shipping shake you have no right to complain that shutaba is incest, because technically speaking if futaba dating ren is incest and you think that akechi is related to futaba, then therefore ren dating akechi would also be incest
not that shutaba is incest (its still a ship i do not like at all and think its very weird because it does def lowkey has incestuous vibes) in the first place, its just that i think its really hypocritical of some goro fans to say that