Martinez, who has been working as a pundit for Sky TV during the tournament, reckons the problem was not so much lack of talent in the England ranks - too much pressure being heaped on the players.
"There are many lessons to be learned from the Under-21s championships," Martinez told the Wigan Evening Post.
"As far as England are concerned, you look at the players who were involved and they are a lot better than the results have shown.
"Either they weren't allowed to express themselves, or they weren't allowed to enjoy the experience as much as they should because of the pressure.
"Of the teams who have done well, like the Czech Republic and Switzerland, it's clear their players are not at the same level as the England players.
"For them, reaching the finals was an achievement in itself, and that allowed them to play with a freedom and an enjoyment.
"We need to help the authorities to find a solution to this problem, to be able to go to big tournaments without the pressure of having to win it.
"Individually we are creating the players, and now it's about creating good teams at the same time."