Simple is an adjective, there is no version of it that fits as a noun.
That would be "simpleton."
Can you disprove that simple observation with any country that plays soccer as its main national sport?
If you say so.
Can you name a sport that is not played by a conquered nation? To illustrate how non-sensical your "simple" observation is, would you say that NASCAR is a sport played primarily by States who practised slavery?