IQ is imperfect and has many issues that haven't been accounted for, nor should it be extended to represent all of intelligence, and many tests claiming to test IQ are completely pseudoscience, if even that, but the general concept isn't pseudoscience. A standardized IQ test has correlation with a number of other indicators of intelligence. It isn't a prefect test and popular culture has greatly oversold its importance, but our society misusing the science, and even scientists historically misusing the science, isn't reason enough to call it pseudoscience.