It may be personal, but I was not impressed by The Programmers' Stone. I didn't read the whole thing this time, but I read earlier versions. My impression then, and now upon reskimming, is that the author defines packer and mapper by analogy (never gives a real definition) and then proceeds to make it "us" versus "them" where "we" are great and "they" are rigid buffoons. So of course you want to be on of "us", don't you? And here is what "we" are like!
I am sure he has a lot of interesting thoughts, but abusing rhetorical techniques like that raises red flags for me. Besides which I am not much of a joiner, and I really hate making decisions when I have less than 3 alternatives on the table. I find that with 2 it is too easy to get into "us vs them" thinking. With 3 I start being able to compare and contrast.