There are plenty of people out there who have failed three checkrides who have gone on to have successful aviation careers. There are plenty of factors that go into initial pilot training. I have see plenty of bad CFI's lead good students down the wrong road because they were mentally checked out. This is not a market that companies can be picky about checkrides anymore. Well maybe they could be they won't find a lot of younger qualified pilots without a few blemishes on their training history.