"Standardized tests are a tremendous burden on all prospective graduate students, but they are a necessary control by which all candidates are judged equally."

I completely agree that the standardized tests are a necessary control for prospective graduate students. However these are not an unnecessary burden for the students for the following reasons.
Firstly most of the standardized tests conducted, test the analytical skills of the students giving all of them a level playing field irrespective of their prior educational qualifications. Of course one might argue that students with prior English education might have a slight advantage over others in the verbal sections, however the Math and analytical sections bring all of them to equal level. Also one cannot deny the fact that as English is the only universally accepted language, it makes sense that everyone considering graduate studies and further working in a global environment should have a good command over it.
Secondly the complexity of these tests is a perfect start for the students to prepare themselves for any sort of a challenge in their future. If one is able to score good in these tests after working hard and studying well, he will surely be ready to take on any challenge given to him in the future. These tests, according to me help the students to infuse the confidence to take on the world and carve out successful careers.
In conclusion I would like to say that howsoever difficult the standardized tests maybe, they are an essential part for Colleges to select their prospective students and tiny step for the students to take toward a successful and fulfilling career. Also due to their universal nature, these tests are a necessary control by which candidates are judged equally.