Earlier quoted context omitted.
I have a pretty negative opinion on ESR these days. I could find technical arguments about many aspects of his good pieces of writing, and much of his writing is not good. His abilities as a coder are not generally remarkable, either. But mostly I don't think he's a good person. I would probably not say "Don't read ESR", but I think it has to be "Read ESR* " *but be aware that he's a polarizing figure and opinions of…
I share your sceptical opinion about ESR, but I concur with the other commenters that The Art of Unix Programming is still worth reading. (In contrast eg to his thing about Bazaar vs Cathedral.)
TAoUP is a good book on the Unix Philosophy, but it's worth noting that the ultimate expression of these ideas (Plan 9) was a failure, and the 'everything is a file' metaphor is arguably incorrect. I hope I didn't give the impression that it was not worth reading, especially in the sense that there are few other good sources for that information (even using Unix is not likely to teach you much about its whys and wherefores). I just think that it should be read in the proper context, and that recommendations should try to include that context.