It is great to have an instantly remorseful WS, but I don't know the percentages on how many do that. My FWH took a while to get to real remorse. I think he did feel bad for what he did, but it took him a while to learn to put his own guilt and shame aside and deal with my hurt when I was triggering. At first, he allowed himself to be overwhelmed with his own bad feelings. I did not stop sharing my triggers with him though and with time (and a good IC) he got better at listening to my feelings and validating them.
I also think that at first, he was in "fixer" mode and since he didn't know how to undo what he had done, he got frustrated. I really had to explain to him that what I needed for him to do was listen to what I was saying and just be there for me--apologize, reassure me, etc. Again, it took him a while to learn that skill. Sometimes he got impatient and wanted to know how many times he needed to apologize. The answer was "As many times as I need." He has worked at it and has come a long way. Now, he sometimes apologizes to me out of the blue--and that feels really good.
There is hope for a WS who is not instantly remorseful. But he does have to be willing to do the work. I would say it took my FWH at least a year, maybe two, to get to the point where he could handle my triggers effectively. It was worth the work and the wait, for both of us.