He also gave a divergent view with his captain Andrew Strauss who had blamed England's hectic international schedule as the reason for the quarterfinal exit.
"I thought that was a good example of playing with fear. We were very tentative and we obviously had a very poor start. We are paying the price for that tentativeness," he said before the team's departure for home.
Electing to bat, England could score 229 for six before Sri Lanka cantered to an emphatic 10-wicket win thanks to unbeaten centuries from openers Tillakaratne Dilshan and Upul Tharanga.
England had just about scrapped their way through to the knockout stages in the first place after a topsy-turvy campaign in Group B.
Although they did manage victories over South Africa and West Indies, as well as a dramatic, high-scoring tie with India, Flower's side suffered embarrassing losses at the hands of Ireland and Bangladesh.
Asked if he agreed with the general assessment that England's World Cup campaign never really gained any momentum, the Zimbabwean replied: "Yes, I would.
"We've been pretty inconsistent with our limited overs performances over the past couple of months. We've had some reasonable stuff, but in the main it's not been consistent enough to get into the final reaches of this tournament.
"To be honest, we didn't deserve to be in the final. We didn't play well enough. I don't want to talk too much about those reasons right now. It's best that we travel home, clear our heads and then we can look back on the last few months and review them properly."
Flower refused to use the schedule, with the World Cup coming off the back of an Ashes tour to Australia, as an excuse - but confirmed that the England and Wales Cricket Board planned to hold a full review of their winter away.
"There's been a lot said about the schedule but we did not have that to the forefront of our minds. We came here to win the World Cup and we have been doing everything in our power to do so. However, we have not been good enough.
"I think a review of the winter would be a very healthy thing. I think (ECB managing director) Hugh Morris has that in mind already. He's put some things in place for mid-May.
"We can learn a lot from the last six months, from both the Ashes success and then our failure out here." PTI