Thanks guys! I'd had no responses for a few days and thought I'd self selected a topic no-one was going to feel inclined to respond to.
All of those reasons are relevant to different people, dependant in their personality, I guess. The thing that gets me about my WS, is that he's always spent a lot of time on social media, and enjoys posting his opinion and responding to others, especially the ones he disagrees with, and posting the fun things/places he gets up to on FB (which is 90% stuff he does while working away). Although he's cut down this interaction massively since I realised (this included inappropriate FB messaging of a female colleague, massive amounts of porn clicking on reddit and many other sites, friend requests on Twitter or whatever by slut women, etc), so it's not as if he's uncomfortable interacting online. Yet his excuse when I asked why he didn't ask for advice on here (after a very lackluster attempt at looking for ANY information to help) was along the lines of not wanting to be told he was a bad person. Despite the fact that I told him for years that everyone was respectful to each other, has been in the same position, and could offer specific tried and tested advice.
He finally joined amd posted after I told him not to come back after being caught in yet another lie about his interaction while away with a colleague he was attracted to. We are having recurrent problems, which he can't be concerned about, as he hasn't asked for any advice since his only thread ran its course! He does read SI some days, but has only mentioned things once or twice, not to discuss how they are relevant to us (which I tend to do), so I don't see anything being internalized or adopted by him.
Similar thing with his IC I pushed him into seeing. The second, because he lied to the first, who I'd asked him to see about his lying! He was resistant for a long time, and they don't seem to talk much about how he allowed himself to behave the way he did (ea/pa), past some labelling of certain traits. Which is now the house to excuse. But that just means ho's core reason is the same now, so another A is just as likely, given the right conditions. His IC seemed fixated on how to act moving forward without really sorting the issues which causes his shit behaviour.
He wouldn't speak to anyone face to face to set up an accountability partner while away, (although after being told to leave, he has done) and wouldn't get one online because he didn't see how it could be useful. Though after reading nofap on reddit, he apparently decided that would be a good idea. I have never told him to restrict that, although I did tell him to stop with the porn, so now I see nofap as his attempt to stop using porn, as I'm sure they were linked for a long time.
So full of inconsistencies. And excuses. Doesn't want to interact online, has to be pushed into it IRL. There's some movement now, but a tiny effort considering this all started to come out in 2016. The progress is way too slow, considering he's going away in a few weeks - for 5 months. No doubt he's recognised himself in this post too.
Want2 - yes, I see how the ego kibbles thing would work!
Sigma - I'm glad you got a lot of help here, I really wish my WS would interact more, he loves to interact on SM, but obviously that gives him good, superior feels...
Coco - maybe not necessary, but I feel it would help him understand quicker...
Cpt - yup, I think this is probably it.
Krystal - I hope there's a lot of internal processing, but it certainly hasn't sufficiently changed his behaviour, as he will still get angry, and choose to continue in a lie if he thinks I can't find out differently - this is a major thing to me. And it hasn't improved.
I don't think I remember the WS you mention - I don't go on that forum much, as a lot of the new WS attitudes give me the rage!
Sorry for the massive vent!!