Matt I see where you are coming from. However, I think you might have missed the idea in the example about building the bomb. While he was arguing that it might have been a mistake to seek out the truth about how to make use nuclear power he was not trying to say that there were not also good reasons, he just chose not to talk about them. He does agree that if the good reasons out weigh the bad or are equal to it then sure he was trying to argue that when the bad greatly out weigh the good. I thnk a better example of his to consider would be the study about how long it takes people to freeze to death in various temperatures of water by forcing people to freeze to death. That study to my knowledge has not produced any real benefit that would not have been gained otherwise.
I was a huge fan of these chapters because before them I was really skeptical about this idea that knowledge is good to care about for it's own sake. When first presented I had taken the stance that the other three truisms are true but the only real reason I care about truth is because I like to be right, because being right prevented mistake and allowed for greater success. This is different than the pragmatist argument in that I still held to the belief in absolute truth I just didn't really care to know about truths that were irrelevant to life or anything I was interested in. After chapter 4's discussion of why I shouldn't really know how many threads are in his carpet I know understand my complaint as not really being relevant to the issue. I was more concerned with whether or not I ought to care enough to find out all truth even stuff that is considered to be a waste of time. However, I do agree that truth ought to be cared about for its own sake but that does not mean that all truth needs to be pursued.