Simpsons joke has a reference. It’s not a Simpsons original.

It is the infinite monkey theorem from the late 19th and early 20th century.

The joke was a reference to that pop culture idea which pointed out that if the infinite monkeys thing is real, there should also necessarily be products that are very close to great works but not quite right.

That's the context of the joke, but it's not the source of the humour.