It also does not mean that new ideas are rejected off-hand. What it means is that all ideas are subjected to the same standards of evidence and support prior to being accepted. If an idea fails the test, it is discarded. Sitchin fails the test as there are simply too many holes in his ideas to be able to use them to draw any valid conclusions. I never say Sitchin is infallible.
Nothing is infallible.
However, if a flawed theory can be successfully corrected, it can still present a valid idea. He presents many interesting individual bits and pieces of arcana and offers some intriguing alternatives to current interpretations. His ideas have great emotional appeal. Unfortunately, there is no level of emotional appeal that can substitute for being correct. Piri Reis was an avid collector of maps and charts.