Hard to explain the nuances and details in the post about the scenario in how it played out. I can see where it appears contradictory. To make it clear, the captain nor myself ever felt unsafe or fatigued. And it was legal on what the company was doing. My objection is along the lines that protocol on which they are operating is backwards and I'm ranting about it. It's putting crews in a potentially bad situation.

The planned flight by itself in a vacuum is just another flying leg during the stormy summer months.
Had that been the first flight of the day, it would have been a nonfactor. But at the end of the day, it is a different story.

In my opinion, the refusal of an extension should not be limited to an automatic implication of fatigue or being unfit to continue. How about the idea that it just isn't a good idea to try and have a crew rush against the fdp in order to fly into known thunderstorms, delays, ground stops, holding, and non fly zones? Why are we constructing lines that even flirt with the idea of having to do that? Out of Atlanta no less. Had I declined the extension, how would my reasoning be viewed upon when facing the Frb?

I can emphatically say that safety was the ultimate concern (not pay grievances). I have no doubt that a safety call is the right call..But the process of having to worry about explaining yourself to a cpo, and or worry about not being protected (pay, jobs whatever) can be slightly intimidating and it clouds judgment.