Riiigght... It takes years to become decent, and almost a decade to become 'really good'. Most junior engineers (first year off the school), or interns are a net negative for the first year. Including the folks that just went to hacker/training type of programs.
Hence most startups avoid them, and only large companies have the means to absorb them in large numbers. The only good right after school engineers I have worked with, had been the types that had started coding at 15. Some of them didn't even go to college, but had at least 5-8 years of practical experience before getting to the point on being hirable to the big cos...
On one hand you are right that CS degree is not required, on the other hand your argument just ignores the fact that it takes years to become decent and at least 5 to 10 years of practice to become really good. Google (and any other large company) is a business at the end of the day.