I went through the Google process too and it didn't come out nicely. First, I have had almost no actual CS lessons in my university, because it was more focused on general engineering and IT management than on code writing. However, I've done quite a bit of code in various open source projects and I've touched quite many technologies... I went through the sets of interviews, and I really seemed to work quite well, ev…
Some companies refuse to discuss that on principle as a way to protect themselves from lawsuits. So you shouldn't take that too personally.
But the fact that it's only "[s]ome companies" that do that still suggests that it's rude and unprofessional behavior.