I guess it matters when you put someone who is a paid Agent of a foreign government on the National Security Council.
In my mind the biggest deal about Flynn is not the secret dealings with Russia or Turkey, it is the display of such incredibly bad judgment. The Trump people even knew Flynn was suspected to be a foreign agent when they brought him into the administration, and they put him in the most sensitive position they could anyway. The recklessness and irresponsibility is pretty astounding.
