^ I can see where they are coming from, as that has been Stannis' MO throughout the show. He has no choice. He must become who he was destined to be. He even said as much to Shireen, in a roundabout way of explaining his upcoming 'choice'.
What makes Stannis' character morbidly fascinating, and at the same time, equally dull, is that there is no semblance of what he wants. What his passion is (beyond sometimes wanting to fuck the Red Woman). I still don't know, and am not convinced, that Stannis wants to be King, in his heart of hearts. It is his rightful duty to fulfill his destiny, which is said that he will be king, so he...must.
Stannis, what do you want?
And, he'd dourly reply, "That is not a relevant question to ask."
Which has driven his plot thus far. He needs an Fi sledgehammer to hit him over the head, as a fish needs water.