It's all perception.
Wesley Crusher was 14 in the first episode. "The Traveler" (Where No One Has Gone Before), not his mother, got him on the bridge by imploring with the captain to cultivate the boy's genius. Wesley got thrown off the bridge in a previous episode. That's the one where his mother got him on the bridge to look around, not as crew.
Name the episodes where Wesley saved the enterprise single-handed. I bet you can't. ("The Game" was the closest one I can think of and he was a 19-20 year-old first year cadet. And really it was Data who saved the day)
Name the episodes where Wesley imperiled the ship and crew through his actions based on inexperience (The Naked Now, Evolution, The Dauphin, etc)
See ya
Tony <--- Slinks back to the dark corner of his basement to continue reading Michael Okuda books