I can understand why - Tracy Kidder made everyone involved with the MV/8000 look bad. The narrative was not compelling either frankly, I've never understood why people found the book so compelling.
Dealers makes everyone look good more or less - like it clearly explained to me why Xerox could never figure out how to commercialize the PARC innovations. The single largest issue appeared to be the incentives the sales force had were not aligned to the kind of products PARC could develop. (though its clear there were other issues with the capacity of PARC to productize something)
A faster Alto with a general purpose operating system and the existing document preparation tools, probably would have significantly outsold the Star - but again, would the Xerox sales force known how to sell that product? I don't think so, and thats the underlying problem.
The Star appeared to have just suffered from the Second System Effect, which compounded the other issues Xerox had.