"Our young lads should now assess how the Dutch players always seemed to be in space.
"If they heed the lesson and work hard to develop to that level then this fixture would have been worthwhile."
The Netherlands rarely moved out of second gear as Marco van Basten's men cruised into next week's Euro 2008 finals with their sixth victory in six meetings against Wales.
Wales goalkeeper Hennessey produced a succession of superb saves to ensure John Toshack's inexperienced side were not humiliated.
"We lost 2-0 but the scoreline flattered us," admitted West Ham striker Bellamy. "And to me, that is not acceptable.
"I don't like playing in games where teams are able to play keep-ball against you.
"All top players or wannabe top players should go away from such an experience and think 'I want to be that good, I want to compete at that level and be in a team that teases opposition'.
"But on that evidence, we are not at that level at the moment. Our goal, though, is to be that good.
"Top teams like Holland are never quiet as they've quality individuals who can unlock the door in a blink of an eye.
"And Wales have a few special ones coming through so I'm hoping for a bright future."
The Dutch broke Wales' three-game winning streak and Robben's strike was the first goal Toshack's men had conceded in almost seven hours.
"Wales is a proud nation and we're a proud team," said Bellamy.
"But we want to come to places like Holland, play in intimidating atmospheres and go away with results. However we must remember we are a team in transition.
"We suffered a lot of international retirements and have been forced to develop young players, we've had to take a step back to hopefully move us two steps forward."
And Wales manager John Toshack said: "We were overall as expected second best to a very, very good side.
"It's got to be a positive experience. We had one or two Premier League players.
"We came here and gave the best that we had.
"Welsh sides have come here in the past and found it very, very difficult.
"It' has been an interesting 12 months. We have played 12 matches before this, we won six, drawn four and only lost to Germany and Cyprus."
Bookmark with:
What are these?