True, a degree doesn't mean they have those traits. But this is where conditional probability comes into play. More people with the degree will fall into this category than those without, because the degree gives them the knowledge to wield those traits effectively. That means that when looking at a resume, you're more likely to get a good hire from one with a degree than without. And several of those traits are positively associated with a degree. Additionally, the floor is higher- while even those with a degree can be a bad hire, a mistake is more likely to be a mediocre worker than a bad one. So you minimize your risks and maximize your potential gains by just dropping the other pile, looking for diamonds in the rough isn't worth the time and money. Especially since the type of person you're discussing won't be easily discernible from a resume, you're looking at phone or in person interviews at much higher cost/effort to have a chance.
One exception I would make is with a personal testimonial of the non-degreed dev's skill by a developer I trust. But you're looking at corner cases there.