As described perfectly in https://www.latimes.com/local/california/la-fi-boeing-max-design-20190315-story.html
TL;DR The 737 was design back in a time when Airbridges didn't exist and steps were used, mandating the aircraft door being very close to the ground.The world has moved on since then, the 737 hasn't
Biting the hand that feeds IT
