It was mentioned up thread that DEC's were having issues, and that a less than stellar sim might be contributing.
Being a DEC brings with it certain additional challenges as well, like not having the opportunity to gain the collective wisdom of a flight department before being put into the hot seat.
At a previous regional airline 60% of DEC's got washed out in IOE, and that's from people who have benefited from 121 training, many more than once.
In this industry you should ALWAYS be worried about washouts. Many good pilots have stalled their careers because of being washed out for one reason or another. Sometimes, it's even attributed by a poor culture from within the training department. Several airlines have even had the distinction of being known to purposely wash people out.