As the others have commented, you need to prove the natural minor is the most popular: AFAIK, it most certainly is not:
- The melodic minor and harmonic minor were developed because of
limitations in the natural minor scale - particularly its lack of the
leading tone - Major 7th.
- In jazz parlance, plain vanilla
minor means Dorian, not Aeolian.
- You will be hard pressed to find any significant works in recent musical
history that are built primarily around Aeolian mode. If you have some, please cite them.
or is it just a "fluke" that it's the most used mode of them all?
That idea is incorrect: Musicians and composers use constructs that work and sound good. It's not a matter of chance.