There are plenty of sats that have just stopped working, even broken apart, for unknown reasons. Telling the difference between a defect and a meteor impact is mostly impossible. Lots of spacecraft have just stopped working for unknown reasons. Until we start inspecting every failed satellite, as we do aircraft, we won't really know.
And note where the 2009 collision happened: over the arctic. This was one polar orbit colliding with a near-polar orbit, right in the danger zone I mentioned above.
There are plenty of sats that have just stopped working, even broken apart, for unknown reasons. Telling the difference between a defect and a meteor impact is mostly impossible. Lots of spacecraft have just stopped working for unknown reasons. Until we start inspecting every failed satellite, as we do aircraft, we won't really know.
And note where the 2009 collision happened: over the arctic. This was one polar orbit colliding with a near-polar orbit, right in the danger zone I mentioned above.