The former Aston Villa defender looked certain to fill the high profile role as FA technical director, but turned it down.
And for the first time he has revealed his reasons.
Southgate told the Sunday Mirror: "Firstly, it should be somebody more experienced in coaching.
"When Howard Wilkinson had the job, no-one could argue. He had won the league title with Leeds and he had great credibility.
"I didn't feel that at my age - 42 - and with only three years managerial experience at Middlesbrough that I had that standing.
"I didn't want to commit to something that was going to be for three or four years when I didn't feel the FA control youth development. The Premier League do.
"I don't think that is ideal. The Technical Director would be seen as being accountable for players coming through with no influence over that process. I had an issue with that.
"I am somebody that likes to take their time over important decisions. I like to weigh up all the facts.
"As I did that, I saw more reasons not to take it than to take it. But don't mis-understand me - the 18 months I had with the FA was a great education.
"I saw how the game was run at the highest level and was given a great insight into coaching."