There were 7 more shuttle missions after that happened so obviously they didn't stop putting shuttles in space after this happened. They also didn't stop putting boats on water after the titanic sank or airplanes in the sky after one crashes. Frankly I'm not sure what these examples have to do with bullet performance but since you brought them up, they illustrate that one "failure" doesn't spell the end of the activity in question all together.
The examples have to do with your argument that one sample means nothing. Sometimes one sample is very relevant, especially if careful examination reveals a weakness in design. To write off a single sample, simply because it is a single sample, is to make statistical analysis more important than reason.
In the shuttle case, there were no alternative space vehicles. NASA did, however, take many very careful steps to try to prevent another failure. If they had other vehicles at their disposal, I expect they would have seriously considered them at that point. The Titanic changed a whole lot about ocean travel.
One bullet failure doesn't stop all hunting, but one bullet failure makes me look for an alternative that doesn't fail due to the same design flaws. Reports of several examples of the same failure make a compelling case to look elsewhere.