>>23358705Shocker Riders and Shadow Moon were both popular and a large part of the fans basically treated them as evil Riders (Heck, an episode title in the tv show and narration in the manga outright called the Shocker Riders "Kamen Riders"). Tohru Hirayama really disliked that though, and it was why he basically forbid them from even doing anything like the Shocker Riders again - note all the "evil Rider" enemies afterwards are monsters with mimicry abilities copying the Rider, rather than someone that by default had a Rider-like transformation. In fact, tv recaps seemed to retroactively try to frame the Shocker Riders like thosemonsters, "monsters mimicking Kamen Rider", rather than even just "monsters that look like Kamen Rider". Shadowmoon only happened when he retired from the franchise after ZX.
I'm not saying there weren't fans sharing Tohru Hirayama's view though. There definitely were and there was quite a stir with Ryuki's evil Riders, but there's a reason they were popular in the first place. Also, both Spirits and Anno's Shin had antagonistic Kamen Riders at one point or another, and those are made by older fans.
It's just an idea that easily fits Rider's "created by evil" origin easily and only was avoided for so long due to a specific higher up disliking it.
>>23358705I mean, yeah, officially the Shocker Riders are just "kaijin" and Shadowmoon is a Rider-like warrior, but not a Rider - although many times inconsistently he ends up outright labelled as a Rider in official material.
Especially the Shocker Rider classification though is clearly just due to Hirayama thorwing a hiss fit over the idea. Considering both tv staff and Ishinomori himself had no issue calling them Kamen Riders.