Why have I never had that issue?
Do people really just write their adventures as a list of predefined conditions and consequences and if players dont meet the condition, the consequence just never happens?
I would go mad. Just write what you want the PCs to learn, who the bad guys are and what they want to do, and what the players get as a reward for stopping them.
All the rest just flows from there?
If your players walk away from your hooks then they don't want story, just throw random encounters from a table at them.