I'm not gonna bother with the OP's pedo-panic shit, being that others in this thread have already dealt with those statements, and I see no evidence whatsoever that Babymetal (or Sakura Gakuin, for that matter) are presented in any conceivably lurid manner.
What I take issue with is this:
Metal is all but dead and a relic of a questionable period in humanity.
First off, I'm curious as to what "questionable period in humanity" you are alluding to. Explain this point.
Second, if you genuinely think metal is dead, I can only imagine that you are either stuck in the genre's past eras and only appreciate metal from the basis of nostalgia, or you don't listen to any metal at all. In the 2010s, metal is thriving, and in both creative and commercial terms, is at its highest point since the early half of the 1990s. On a commercial level, have a look at the sales figures for recent albums by bands like Iron Maiden (Book of Souls) and Anthrax (For All Kings), and then compare those sales to albums released by those bands 15 - 20 years ago. Newer bands such as Gojira and Ghost aren't doing too shabby in the sales department either. This is all in an age when practically any album by any musical act can simply be stolen online. People are BUYING these albums in strong numbers. From a creative standpoint, it's much more subjective as to whether or not you think the overall quality of metal is at a peak, but I've been listening to metal for roughly 25 years now, and I strongly believe that it is. With so many subgenres and sub-subgenres now, there is a constant appeal to practically any taste. There is also more pressure for bands to compete for the attention of the listener, simply due to the fact that there are so many metal bands out there, and this lends itself to better albums, even for old stalwarts like Megadeth, who've recently released their best album in fucking decades. Compare this to the genre's mid-90s slump, when metal in general was quite stagnant, and only black metal, the power metal revivalists, and the burgeoning retro-thrash scene had anything genuinely exciting to offer.
tl;dr Bro do you even metal?