The Aussies were beaten by 74 runs in Colombo on Friday as the Windies booked their place in Sunday's final against hosts Sri Lanka.
"In hindsight you can do things differently, but the fact is that we just got outplayed," said Bailey.
"There are no excuses. The best team absolutely won the game tonight. There is a gap between your best and worst cricket, and we did not play good cricket at all."
Bailey averaged 42 with the bat over the course of his side's six matches at the tournament.