It's not so much people ragging on ReimuC as it is that people praise ReimuA due to her powerful-yet-simple shot (MarisaA suffers from reverse-focus syndrome, MarisaB requires fancy shotgunning or unintuitive firing directions, everyone else is just plain weaker) and her ability to gap. That said, I personally don't like ReimuC because of the aforementioned power problem, the trickiness in making the most of her shot, and that I can't think of a single practical use for Ayaspeed for anyone not named GODrake (and it tends to get me killed should I forget Ayaspeed exists when I stop firing, such as during Parsee's second card). I hear she has the best bomb in the game though, so she's not all bad.
Anyway, congrats on your accomplishments!