OP, in your reading have you got to the part where you learn we're each an "experiment of one?"
My expression on reading about higher cadences was the same as your -- "Holy smokes!" But I tried it. It took a while to get comfortable with cadences in the 80-90 range. Lo and behold, my knees stopped hurting after hills. I'd even say the cadence on my Cateye Astrale was one of the keys to finishing my cross country ride ten years ago -- I wouldn't have made it without the gears and the reminder to gear down going over the Appalachians and the Ozarks.
Even now, it's funny how often I feel bogged down, can't maintain speed on this low grade, then I look down at the display and shift down. Next time I look, my cadence has gone from 70, not just to 80 but up to 90 rpm, because I sped up as the hill got steeper. That's my motivation to keep my cadence up (besides my knees like higher cadences better!).