Note: While the following is all highly speculative as it must be, and though I'm wont to talk about people rather than actual issues, this case seems to warrant it.
I've been looking into Greg Maxwell quite a bit recently. All the core devs actually (except Wladimir), and the blockstream people. Greg seems a sincere and extremely intelligent fellow with the right kind of bent for the job. The way he
knocked the wind out of Stellar's sails on Hacker News was quite something, just as one example.
However, I do sense that he and Gavin have a bit of an oil-and-water dynamic going on. I have never seen them debate directly, though that could be because he was busy recently and "caught a bit flat-footed" on Gavin's proposal, as he said. Seems like classic nerd/jock or cat/dog dynamic (I realize Gavin's also a nerd) with weird passive-aggressive miscommunications aplenty. The thing where Gavin said he spent an afternoon reviewing Greg's idea only to not have it acknowledged reminded me of that especially. Still need both sides of the story, and Gavin has his own subtle ways of being bitchy at times if you read between the lines so I won't draw conclusions.
It's most interesting to me, though, that Gavin and Greg have both proposed a series of 50% increases, yet these two seem as you said the main sticking point for this debate. Pieter seems not very entrenched, and Matt I suspect would go along with Greg and Pieter. Luke I'm not sure but on a hunch I'd say he would go wherever the action is dev-wise, despite his principled stances and eccentricities. He's not Mircea Popescu. Adam overall seems eminently reasonable and would probably not do anything disappointing, but that's just my cursory read.
Perhaps it's time to work some social magic to have Greg relax his position a bit. Since I've been reading almost all his posts, I've noticed he gives little glimmers of sunshine at times. He's not an unreasonable person, and despite his hardline stance I can tell he wants more than anything for Bitcoin to succeed. I could swear he gets less accommodative when Gavin's in the thread, though. The rays of sunshine seem to be buried deep in the comments when he's talking to someone else in a thread where Gavin is absent. Maybe just my imagination.
There are issues among such a group of people that we probably can't hope to understand. The politics, the interpersonal clashes, the miscommunications, the lingering grudges tinting things. Again, I think your implication may be right, this may be more a social issue than a technical one.