>>2890263that's not really the actual story though.
A lot of it comes from uma musume being bizarrely successful. It came out of nowhere and completely fucking dominated japan mobage sales charts. And like you mentioned, yakuza do actually run the "legal" forms of gambling in Japan. This isn't really conjecture, it's just how Japan works. What is conjecture, however, is that uma musume is/was basically being used as a money laundering front, which would explain the bizarre amount of revenue(yakuza take illicit funds from prepaid/gift cards/etc. and funnel them into a subsidiary they control and it's "clean").
The further joke is that the IP holders are every staunchly anti-porn of their characters and are more trigger happy with takedowns than Nintendo. Hence - make porn of the horses and you risk the yakuza breaking down your door to bust your kneecaps.
