Please try to avoid gatekeeping in public, particularly with regards to what people read.
Please?
Please?
Anyway, if it's gatekeeping to suggest that people should pursue personal growth through their own authentic interests rather than reading as a chore to be "more efficient", then call me president of the gatekeeping club for all I care.
If someone reads short, easy to read books for any reason, that's dandy. I'm sure they'll get something useful out of it.
On the other hand, are you reading The Art of Computer Programming? (Oddly enough, I can currently answer yes, since I've been playing around with the section in Seminumerical Algorithms on testing random number sources. :-) )
Also, is it actually "gatekeeping" to say that arbitrary numeric goals optimize for a different kind of reading than what you'd get with different kinds of goals?