It is the title. I havent read further. Nobody wants to be thought of as 'the new' aka green behind the ears one. Change the title to 'letters to the experienced developer', slight adjustment of text (although mentoring applies as wall; and what is good for the new one is good for the seasoned), 3. grab the cash.
Could be out of politeness, but could also be they dont see it. People might read it and think it is really a good book for the target audience (which it probably is); they probably dont see themselves as the target audience. Also they read the whole book and maybe it was great for them, and their feedback was honest. My claim is the people who would benefit from it wont get past the title, but I have no idea how to validate this idea.
