Quote from SacredGoogle. Check out this article. Google prefers college dropouts over college grads because straight-A college grads lack "intellectual humility." Which, simply put, is having your intellect fail you in a situation and now you have to accept the consequences and deal with them to overcome the problem. Google believes those that have sat in a classroom for 4-8 years and finally passed have felt the feeling of success enough to the point that they have forgotten the feeling of failure. Thus, when they actually come across difficulties, their knee-jerk reaction is "It's someone else's fault" or "I didn't have the resources required to solve it." Where as those that have been passing with Cs and Bs obviously don't have intellectual superiority, but with that lack they make up in capability of still being able to sustain themselves even with that crutch. And I'd prefer survival skills over smarts any day because it transfers when it really matters.
No where did Google say they"prefer" dropouts over graduates; you may have thought that due to the bias of the article. The crux of the information says that they are looking for people with X qualities over a good G.P.A, but that does not imply that they prefer one of the other. This is a misinterpretations. They are looking for qualities in people, which can exist for both graduates or dropouts. The majority of their employees are still graduates, only that there is a trend showing there is an increase in the number of those who do not go to college (they comprise of 14% of teams).
And you do realize that the things you mention are just generalizations made by Google right? They are not representative of a typical college graduate, and just as there are exceptional individuals who do not have a degree there are bound to be some who have one. Just know that some need the pressure in order to reach the level they are at, and not all have the intrinsic drive to do it on their own. Not everyone has the determination of Mark Zuckerberg or Bill Gates who can independently pursue their passion. This is rare, but Google realizes that these people exist and are out to find the needle in the haystack. The mentioned people have an incredible work ethic (from what I've heard in interviews) and those who score poorly do not always possess this trait. I find it hilarious that you associate those who score Bs and Cs with having the desirable qualities of an employer. That "may" be the case but is definitely not a certainty or probability. More often then not these are the slackers and the ones who are making the excuse "I didn't have the resources required to solve it".