[Matrixbeast]

Focus will always be spotlighted on the red ranger, even if his story isn't that important (See Ryuuranger). It's just a fact of life. It's nice when they give fair share, but it's just how it goes.

Go-Busters just didn't catch on with kids. They aimed for something new and failed. Sucks, but it happens.

Kyoryuger did work. It was popular, energizing, and excited. I hated it, for focusing so much on Daigo that his nickname of King was too on the nose, but that doesn't change it's success.

Western fans opinions don't matter. At all. Toei thinks Gekiranger was the Toku equivalent of the Hindenburg despite it being an explosive hit in the West. I don't know how well ToQ did in Japan, though.

Ninninger didn't work because they basically distilled Sentai into a formula and went from there, rather than do anything interesting.

Zyuohger isn't anything different. We see a red focus already (Though not as overwhelming as Kyoryu), common Sentai staples, and basic characters (They can grow, don't get me wrong, and I do like them. But they're not anything special as of now (That being 11 episodes in)). You could even call Zyuoh as disappointing because it's playing everything safe. There's also no collectables which means toy sales might not skyrocket, which could spell out "Failure" in Toei/Bandai's eyes.