This information is wrong.
Well, if Bitcoin was centralised in the sense that it was being operated like a banking institution or run like other firms, then the value would have been affected because of how the management would have been run. Another factor that contributes to the value of Bitcoin is its supply. Already, majority of people buy Bitcoin every day, and even if all the Total supply of Bitcoin were in circulation and perhaps all the Bitcoin were being distributed among all the Bitcoiners that we have, each person would not even have up to one Bitcoin. So, the supply and demand of Bitcoin is also one thing that keeps its value high.