I don't disagree but I think commonly you are missing one of two things that are necessary for a proper design:

1) time to design it 2) knowledge of exactly what it needs to do today and in a year

Sometimes you're missing both.

In which case I think you can prevent contagion from being too terrible by enforcing smaller modules and single responsibility in a compositional way. That doesn't require as much knowledge of the future or time, but just requires you to avoid high-surface-area interfaces that end up with lots of behavioral variants controlled via parameters in a nesting-doll style. Instead, move your config/parsing/behavioral decisions to the edges of your logic instead of letting them seep into all your underlying models too.