I think the hardest part is that our little weather vision app isn't perfect by any means. It often predicts areas of pretty rough turbulence, but half the time it says nothing about areas where we do encounter at least some light continuous. I completely agree that none of you should be placed at risk of injury for any reason. But it's also pretty hard to say conclusively on a lot of days, that it's gonna be perfect or even good, for X amount of time. Our crystal ball is a lot blurrier than that. I get the impression with some FAs that they mistakenly believe that we know exactly when it will start, and when it will end, as if it were some waypoint on our flight plan. Which is totally not the case. On the other hand, it's also pretty hard to justify not offering service on a 5+ hr transcon (that's what my story was from) because there were a lot of pockets of turbulence forecast over the plains/upper midwest. However I also wouldn't be comfortable telling a crew that they *must* do the service if they aren't comfortable.