Kamen Rider always been known to be more darker and serious then Super Sentai. I know Den-O and Fourze have been campy, but they still had their serious moments. I think Super Sentai being dark does not sell well in Japan because Sentai always been known to be light hearted and campy in Japan. Some people believe JAKQ and Go-Busters bombed because they were too dark for younger kids.

Gaim being the example for that one.

The darkest show in PR history is easily Time Force which is ironically probably the maturest. I was really surprised the villain was original to the show, given the kind of themes his involvement in the show added to the whole thing. That was some adult shit.

Also you guys all know how I feel about Rider compared to Sentai, Rider blows sentai out of the water and then some in basically every regard.

Yeah, Rider is indefinitely superior to Sentai to me, as well.

Same here. I feel it's because most Kamen Rider series have enough aspects that viewers of all ages can enjoy.

I've called Turbo mismanaged plenty of times before. :lol And RPM, while awesome, feels more like a primetime action drama in hindsight rather than a PR season.
Is that bad? I don't know. Personally, I feel that style would be better for an American Rider series.
Which is probably why it doesn't feel traditionally "PR." (And probably why Disney never aired it.)
I wonder what RPM would have been like if it wasn't the last Disney season...

Turbo did well enough to warrant In Space.

And I agree, the near extinction of all life on earth does not make RPM good, the character interactions and development make it good. Ziggy risked his life to help the less fortunate, Summer realized all that glitters is not gold, Flynn achieved his dream of being a real hero, Scott proved his valor and merit to his father and left his late brother's shadow, Dillon was basically cyber-Andros in a muscle car, and K reconciled her hand in the creation of an evil.

Man I really wanna watch RPM again.

Well as Locke said earlier in this thread a good amount of his fandom is made up of both adults and teens.

Now for teens for a story to be dark there needs to be, blood, sex, and drugs involved just so kids can learn "Say no to drugs!", or "Don't get into fights or your parents will ground you!" (Because if the parents of the power rangers found out they were the power rangers they would be grounded for eternity lol).

Now as for the maturity aspect for PR, people think DEATH!=Maturity but if it doesn't do anything for the character then, it's pointless to include death. Now another thing of the maturity, people think Sentai is more "dark" and some of the older ones are, but it all boils down to the language and how it's translated, since when people hear things like Zyuden Sentai Kyoryuger, they are like awesome! But they hear Dino Charge they're like lame! Even though if they knew that Zyuden Sentai Kyoryuger translates to Electric Beast Squad Dinosaur Ranger they'd be like still cool so they don't look dumb.

At the end of the day it's all about what they do, now I've never seen RPM, Time Force or most of PR for that matter but from what people say about them they sound great.

Now all in all as others have said it boils down to how mature the viewer is, whether or not if they are embaresed about being in this fandom or not. Now I got into PR to see the effects of the Fights, Zords etc. So I basically just said what others have said.

I think all the series needs is to not talk down to its audiences. That's mature enough to me.

This, precisely this.