I'm sorry but no.
Recasting your dot before they fall off or after they fall off isn't hard. It's like saying applying them in the first place is hard, it isn't.
Knowing when to refresh or not would have been hard IF you didn't have addons letting you know the power of your dots and telling you if you should refresh or not. Or stuff tracking your trinket ICD/buffs.
It didn't add any difficulty, you just had to look at your addons.
Now, leap of faith and etc, I can agree than those spells were something that could show you who was a good priest and who wasn't, aside from a dps/hps point of view.