I agree, mostly, which is why I have retests.
Additionally, I do have other things to work on. Take algebra. Section 3 is writing and graphing linear equations. Section 4 is systems of linear equations. Johnny can't do 4 if he truly doesn't understand 3.
I get the idea that students take different amounts of time to master material, but at some point, it is better to tell him that retaking the course would be a better option than retaking every test. I don't mind if he completes algebra I in two years.
That image is being very disingenuous, though. Those exams don't lead to more learning ... they're the end-of-course exit exam, the final exam, the high-stakes test that so many reformers hate.