[1rudeboy]

Your observation was “simple,” yes. Used as a noun, not an adjective.

[Sam's Army]

Others mileage may vary here, but in my experience the folks who complain the most about soccer never played ANY sport at a competitive level.

Those who have played something competitively (i.e. above little league) typically seem understand and respect athleticism across multiple sports; without the insecurity of projecting their own inability to play ball--no matter what type it is.

[IYAS9YAS]

Your observation was “simple,” yes. Used as a noun, not an adjective.

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?