To some extent, the situation you describe is inevitable in any field. The
question is, with what attitude are these "certain books" approached? I
recently heard a colleague say that her goal in teaching literature was to
help students understand why the canonical works were great. In her view,
if a student says that "The Scarlet Letter" is fundamentally flawed, her job
is to help the student understand why he or she is wrong.
To some extent, people have been talking past each other on this point.
(For instance, the terms "canonical" and "primary" have been mixed
together.) Are we talking about texts that have a certain institutional
power because they're on graduate school exams, texts that have a certain
disciplinary power because all the people who we want to read our articles
have read them and value them, texts that many of us roughly agree for the
time being are worth talking about, or texts that are great whether the
unwashed masses are capable of realizing it or not?
Devalue definition? Hmm. Seems to me that this discussion is in dire need
of some acts of definition.