A degree and or graduate degree simply opens the door to allow one to enter a field of employment, limiting the pool of those that are considered qualified. GPA has and still is a driving factor in the employeers decision making process in relation to who they hire. So, in some respects, a degree, and how one performed still matters, obviously depending of the field/profession.
But, as had been pointed out, a degree and or GPA just tells us a persons book knowledge abilities. It's a very small piece of the whole person. In college/university I had a department heads daughter befriend me. She was a nice and wickedly smart girl. But she was rebelling against her father and the education system, so her grades suffered. She had a saying her father absolutely despised, "D's get degrees. Despite her being on academic probation, she earned her degree, proving her point to her father, and later becoming very successful in her field.
I also taught during my graduate program. For me, grading papers was the most difficult portion of teaching at the college level that I experienced. However, a fulltime professor quickly help me figure it out. The issue was that with exception of very few papers, they all failed to address the assignment. Many, never hit the assigned topic, other than a simple mention of it.
My point here is that GPA/performance/a degree can be misleading.
With that said, some of the smartest people I have met, have never obtained a degree. They simply found their own success. As for me, I was wanting to move up the ladder, start a family...The company I was working for had adopted a highly qualified policy. It finally hit me that without a degree, my skills, knowledge and abilities were moot, with a highly qualified policy and me lacking a degree.
Some fields eliminate some exceptional people, because of a lack of a degree, others, simply don't require a degree. It's not our formalized education that makes us who we are or are not. It's what we chose to do with what we have, persistence, stick-with-itness, and so many other qualities.