Grades Are A Bad Thing?

If we are to believe this article from Slate, grades are a thing of the past and need to go the way of the dinosaur.  According to the author, several studies have been done that show grades as a major source of anxiety.  They keep students from learning because they are so stressed about what the grade says about them.
It does make one wonder just what they are advocating in place of the grade scale.  Then we read further that they are advocating that schools be a place where we set students free with lots of free time and says that students in that kind of setting will seek out more challenging problems.  Right.  Have they seen what teens and pre-teens are like?  Do they know that kids with spare time on their hands will not choose to read and write, but to screw around and goof off?
While the educational system is not perfect with grades, it is the best measuring stick to show us that things are being learned.  Given that the world itself is built around daily tests of our skills and daily grind that has stress for every last one of us, does it not make sense to prepare students for the challenges of the workplace rather than sending them off to a 5-6 hour screwing around session?  Given that they want to do away with grades, how would parents keep track of what their child is learning?  You would have to trust teachers to do their job well and we have seen several examples of teachers that are simply there for the paycheck.
Calling for grades to be eliminated is ridiculous.  There needs to be stress and measuring of the learning that is taking place.  Now, that said, I am not a big fan of standardized tests that students are forced to pass.  They have only led to teaching to the test rather than teaching the basics that a student needs for the world.  
I have a simple solution.  Teach the basics like reading, writing and math.  When a student doesn’t do well in those subjects, they fail until they are ready to advance to the next level.  When you get a little older, teach critical thinking so that students aren’t just taught one particular worldview, but many and are given the tools to think for themselves.  When they have that kind of tool, you set them up for lifelong learning and then all of the rankings that have the US somewhere between Paraguay and Jamaica in terms of education will take care of themselves.
Grades should not be flushed.  Far from it.  They need to be the measure of what is being done in the classroom, with the caveat that the local school has the right to make decisions that are currently reserved for the feds or the state.  Education is something that needs fixing, but taking away the incentive to do anything is not the way to do it.