I'm getting pretty old so I have experienced multiple waterfall projects. The comic should be
You want to go to mars
You spend 3 months designing a rocket
You spend 6 months building a rocket
You spend a month testing the rocket and notice there is a critical desing flaw.
You start over again with a new design and work on it for 2 months
You spend another 6 months building it
You spend 2 months testing
Rocket works fine now, but multiple other companies already have been to Mars, so no need to even go anymore.
pretty sure they're saying waterfall for building a rocket because that's literally how NASA builds a rocket, including the software. It's terrible for building anything other than a rocket though, because the stakes aren't high for most other projects, at least not in the way that a critical mistake will be incredibly bad.
i take you have never heard of the V-model. basically you climb the waterfall back up to verify everything. most things that fly within the atmosphere are done that way. pretty sure NASA would do the same.