Checkrides and PCs aren't that hard. Study hard, show up prepared, have a good attitude, and be willing to learn. One or two busts isn't too bad, it's the people with 4 or more busts that are problem childs that shouldn't be doing this job. The Colgan guy at BUF is an example, as was the Captain of the Learjet crash at CAE. She had 4 previous checkride busts, and got hired at Executive Jet without the normal sim check given to applicants because she came "with good recommendations." This was a 3,100 hr pilot who aborted well above V1, despite her FO saying "go" and "go go go" meaning take off.

One or two failures is a bad day. 4 or more is a repeating pattern of someone just not cut out for this job. It's an easy job, but not everyone is made for it.