THE REASON BAD PILOTS DON'T GET WEEDED OUT IS THAT THEY AREN'T BAD ALL THE TIME. THEY MAKE BAD DECISIONS OR SHOW A LACK OF SKILL EVERY ONCE IN A WHILE AND THEIR POOR PERFORMANCE USALLY DOESN'T RESULT IN A CRASH, AND OFTEN GOES COMPLETELY UNOBSERVED.
COUPLE THAT WITH THE FACT THAT "GOOD" PILOTS ARE SUBJECT TO THE OCCASIONAL BAD DECISION OR CARELESS BEHAVIOR THAT RESULTES IN A CRASH.
I PREACH THAT WE MUST ALWAYS BE OUR WORST CRITIC, LEARN FROM OUR OWN PERFORMANCE, AND RECOGINIZE THAT WE ARE CAPABLE OF SERIOUS MISTAKES, OR JUST BAD LUCK.
Good pilots have crashes, too. One mistake is all it takes. A good pilot accepts that mistakes are inevitable and works very hard to delay as long as possible that mistake, or make the mistake as small as possible when it comes.