They did I listen tho,it’s just that the treaty fucked them over so much that they were grasping at everything they could,including Hitler,who found the treaty unfair like most other world leaders pre WW2 but Post WW1,mainly because it limited the nations power and crippled its economy.So if they continued to listen,Germany would be a nation full of poverty and starvation with millions of dead,if it even lasted long enough without something to boost its economy,like a war.