When racers spin out of control, it is the event staff's duty to raise caution that there is danger ahead, but that did not happen. The situation at Talladega last night created the perfect condition for wrecks, pileups, and for debris to fly and hit the audience. Wreckage is common in racing, and many drivers were surprised a yellow flag was not raised.
Yellow flag conditions are there for a reason. This is because such tools let everyone know what is going on with Nascar conditions. There should perhaps be more regulations and signals for the audience, so they feel more included in what is going on in Nascar officials' heads. They were in the right.
If it's questionable if a yellow flag should be issued in NASCAR, the answer is usually Yes. Why should you ever take a chance when lives are at stake and NASCAR speeds are as fast as they are. The drivers would argue this, of course, so the yellow flags are really to protect them from themselves.
The yellow flag has been overused recently. Pro drivers are paid top dollar to be the best in the world. These men are more than capable of navigating minor obstacles. When officials start throwing caution flags for minor incidents then the audience is forced to watch a race at half speed.