Levite
Higher and Higher
Because most Jews stay away from the Kabbalah like from wild fire. it is too esoteric. and the word 'mystical' brings bad connotations that most Jews want to keep away.
The Kabbalah is not THAT old. it is rooted in Middle Ages Spanish work which was greatly influenced by blended Christian esoterics. it was produced during the time that a more Enlightened Spain under Muslim leadership has fell again into Christian hands and thus began the history of the Reconquista and the ethnically cleansing of our people from Spain.
It does not measure to the Hebrew Bible. what it does however is take the Hebrew Bible and give it a mystical and highly romanticised interpretation. the kind which rabbis have forbidden Jews to indulge in for centuries.
First of all, most Jews don't stay away from Kabbalah like from wildfire. They mostly are simply ignorant of Kabbalah because they haven't been taught. Most of the Jews I have seen who learn about Kabbalistic concepts, or whom I have taught about them, find them both fascinating and refreshing, and have said that they like having more metaphysical and spiritual options on their palate to work with.
Second of all, Zoharic Kabbalah is rooted in the work of Spanish rabbis of the Middle Ages, though I think most scholars of Kabbalah would debate the degree to which it was influenced by Christian mysticism. But pre-Zoharic Kabbalah actually seems to have emerged from the radical reinterpretation in 11th and 12th century Southern France and the Rhineland of Hekhalot mysticism, which as you know was widely practiced in Babylonia from about the sixth century on through the turn of the millennium. And Hekhalot mysticism was itself a reinterpretation and expansion of Merkavah mysticism, which was practiced from the earliest beginnings of the Tannaitic period (turn of the Common Era) through about the seventh or eighth century.
Mysticism has always been part of our tradition, in one form or another. It is today nearly universally accepted as a legitimate branch of the tree of Jewish thought. And though many have quarreled during our long history about this Kabbalistic doctrine or that Kabbalistic doctrine, or (in the Middle Ages) about Kabbalah versus Aristotelian rationalist philosophy-- which included its own rationalist form of mysticism, it doesn't seem to have prevented most of our greatest rabbis from being Kabbalists or mystics of one sort or another.
I think this is one more place where you might want to differentiate between what "Jews" think and do, and what you personally think and do. Because the two are not synonymous.