In The Matrix Reloaded why does the architect create multiple versions of the matrix and the one?
The one is not a creation of the architect. He is a statistical anomaly occurring naturally within the Matrix that has the potential, as we can see in Neo, to be a significant threat to The Matrix and the machines. Understanding that this statistical anomaly is destined to cycle through the Matrix endlessly, possibly destroying it eventually, the machines create a scenario that allows for the existence of the anomaly, even nurturing its existence to an extent, by perpetuating the prophecy through each cycle of the Matrix. When the One selects his twenty-three people to start anew, the prophecy is handed down and the resistance carries it through until the next 'One' is discovered and awoken to lead the resistance and so on. Repeating the process over and over is, I think, best described as a necessary evil for the machines, making order within the Matrix possible.