"Banned" may not be the right word, but I do agree it's the wrong question. Story points and velocity measurements are about giving a reasonable guess about what's "likely" to be completed at any given point in time in the future, with bigger error bars the further out you look. Agile projects don't "complete" so much as a decision is made to release at a given point, and everyone is happier with agile in an environment where there's an expectation of multiple, continuous releases.