Honestly, these drive me nuts. Hate 'em.
Alright, I'll allow a short, as in 3 page max, introduction if there are mitigating circumstances that it is important that the reader should know, OK. But 50 pages of prologue and introduction? No. I am not that interested in your thoughts on the book. Write the fricking book and have the balls to send it out in the world without your endless maundering on about it. For the sake of all that is good in this world.