Let's be clear here. Not all kabbalah is nonsense. There is real kabbalah and there is fake/'marketed' kabbalah that teach it to goyim and take the torah and mitzvot out of it. But kabbalah, the real kind, is very much a part of Jewish tradition. In academic circles the origins of the zohar came under scrutiny or dispute, but elements of it are certainly representative of an older tradition, whether exactly a manuscript reauthored later or not, and that is a very complicated issue that cannot simply be summed up on a forum like this. It would take someone extensive researching to come to a conclusion, and even then, it would not be one way or the other black and white.
But in the traditionalist/religious circles, kabbalah is certainly a component of Jewish thought and has a big influence on the Torah world. But any time kabbalah is used without Torah and mitzvot as the basis or to replace Torah, mitzvot, halacha, etc, then it is not truly kabbalah and not legitimate. Also, anyone claiming these days to do "practical kabbalah" is most surely lying, and this is also forbidden as far as I know. I think the red wristband might fall under this category of scams. For ashkenazi Jews, kabbalah is not studied until age 40 and with a significant knowledge in Torah first. Even for sephardim where this age limit does not apply, one should not delve deeply into kabbalah without a strong background in the basics in Torah.
Some around here have a habit of trampling on kabbalah, and I would say this is deeply misguided.