The SAT is basically a test of your potential to succeed in future classes and on future tests, independent of the content required for those exams - yeah, critical thinking is a part of it, but so is a basic foundation in reading comprehension, writing ability, and elementary mathematics. Those are all things that should be a baseline going into college, and which will affect your ability to succeed on all future examinations and in all future classes. In other words, it's more a measure of overall test-taking ability (which encompasses reading the questions, anticipating the author's intent, critical thinking, and performing basic calculations) than critical thinking
Memorizing arbitrary vocabulary and roots is a way to game the expectations of the SAT, not what they are intending to encourage.