Well, alright, I might as well share some facets of Seriphyn's behaviour, building on Morwen's points.
I am eternally grateful to CCP for doing the Sansha Heavenbound thing on Seriphyn, as it ultimately turned him into his own character, far removed from myself (though Seriphyn's exploration of classical liberalism in a decidedly non-liberal universe has had a scary influence on my own RL beliefs). As a result of those events, Seriphyn has become somewhat of a
Byronic Hero. I never consciously pushed him in this direction, but at some point towards the backend of last year, I read the page and was like "Welp, that's Seriphyn".
A lot of it also comes down to perspectives and contexts. For example, Anslo has said in this thread he does not see Seriphyn as arrogant and vain, and equally Lyn does not understand the dislike either. Interestingly, on Lyn's point, Seri's venomous sarcasm about the Federation fits his Byronic trait (the 'jaded and world-weary' bit), regarding the interplay of cynicism and the pursuit of ideals. Seri sees his own beliefs as superior to all others, and it happens these beliefs fit with the Gallenteans (he did grow up as a Gallentean after all, and he certainly didn't invent his own beliefs). However, he does not see the Federation as contingent with being Gallentean at all.
Anyway, some characters will see Seriphyn negatively, others will not. Scherezad has been with Seriphyn for
over a year, and one does certainly does not RP with a 2D character for that long. Seriphyn has been said to have an "infectious aura", which fits the 'charismatic' element of a Byronic hero. But in the Summit circle, Seriphyn is disliked, for a set of interconnected reasons. The first is my patent refusal to RP Seriphyn as a 'popularity sellout' (not accusing anyone of being that, that's just how I see it for Seri). For example, the Scherezad theatre event yesterday was attended by numerous other characters. I could have RPed Seriphyn as someone who thoroughly and outwardly enjoyed it for the purposes of scoring points with the other characters. But that would be out-of-character for Seriphyn. He saw it as a bunch of pretentious ponce (as Morwen has elaborated on) that self-aggrandized the indigenous culture with a bunch of historical wankery. This fits in with the 'rebellious' and 'disrespect for privilege' tropes of a Byronic Hero. There is no way I would have RPed Seriphyn as anything else in that event. As an aside, Seriphyn's respect for Caldari culture comes from their hard work and efficiency, not "bullshit tradition".
However, it's not "edgy for the sake of edginess". He's with his girlfriend, Scherezad, and thus his reactions were tempered and modulated because of her presence. Ultimately, he caved in and ended up enjoying it, because I felt that the most organic development of an individual having to sit and watch something for several hours. It's not a case of 'Oh this is wankery look at me saying it's wankery!'. But some people are more interested in the 'getting along' RP and, eh, well, fine. That RP, I feel, has an entirely different purpose to the sort of RP I pursue. The 'getting along' RP is motivated by desiring OOC approval, which again is completely fine. When Seri rejects the clique and all that, this has an OOC effect as well, because I feel some people take it personally OOC as well. I don't believe in the IC/OOC divide being 100% solid; that's just human nature. I don't really hold anyone in contempt for bleedovers.
So, a lot of the dislike to Seri I find originates from the "getting along" semi-casual RP bloc. I've had one character message Seri saying that she sees Seriphyn as "objectively a better human being than the majority of the people in the Summit". And I call the "getting along" bloc as semi-casual, but even relatively casual RPers like Seriphyn. And this says nothing about when Seriphyn RPs with Gallente loyalists, where he is universally liked.
Shit, this is a really disjointed post, but then again, I like it that way.