With Facebook, I at least had a phone interview and could run post-mortem on what I might've messed up there. Google appeared to just toss my resume down a black hole.
I later decided that really, I didn't want to be a programmer, I wanted to found a startup. I was still in school and not 100% sure of myself at this point, so I applied to 1 programming job at a small place in Connecticut. I got a phone interview and then a rejection. I blamed my "failure" then on my lack of interest probably showing through.
Sadly, I had the same null feedback experience with many seed funders that spring. Most of the time it was a black hole. 2 (Lightspeed and IO Ventures) of them gave a brief explanation, which matches some (but not all) of my own post-mortem analysis. I think that given the high probability of rejection, rejection feedback significantly increases the value of applying.
While I don't think rejection from a place like Google is necessarily "random," I would certainly agree that it rarely provides actionable info.