A couple of people did studies showing that serious, prolonged static stretching (e.g. 2 bouts of PNF stretches, contract then relax) reduced muscle tone and slightly reduced max power in a test immediately afterwards.
So, as usual, everyone overinterprets these things and says all static stretching is redundant.
A normal runner in my day used to do 15m jog, then maybe 5min stretching (with maybe 30sec max on one muscle), then a bunch of drills (high knees, heel flicks, bounds) then strides, which would have the exact opposite effect and bring you back to being bouncy for your race.
Here's how I think about it: yes, the ideal is dynamic warmups before and static stretching after. But if I feel a particular muscle is a little tighter than it should be, I will most definitely give it a little stretch pre-training if that helps restore normal mobility. And I think almost every track athlete I know instinctively (and my parents' dog, come to think of it) does the same...