Simplicity of Islam

Once I asked a man , who newly had accepted Islam, what aspect of this faith interested you most, to become a Muslim? He said " It's simplicity".
This made me think twice, how easy and simple was the original message that a group of mostly illiterate and Bedouin Arabs were able to understand it and act upon it with such strong belief and devotion, that changed the face of the globe in a little more than a decade.
I further began to question how and who distorted that simple message to become so complex , complicated and times confusing?