Its pretty obvious that some degree of pandering was done with the S.S. ClairTen. Or am I expected to believe that the choice of the term "OMG I SHIP IT" was totally coincidental? It reeks of bad fanfiction because its such a sharp departure of character for Marten. I could buy it was a little set-up. Maybe a panel devoted to Marten playing out the "big speech in his head" and deciding to go ehh screw it, perhaps on the advice of Pintsize....who has actually given decent advice in the past.
So yeah, its pretty terrible. But that's why I like it. It has something of an endearing charm in its badness
Look at the little number at the top of the comic. In pixel size it's not very big. In absolute value it's fairly large. Now knock off 200, to account for Guest strips, and dramatic endings. What's left (2615) is a reasonable approximation of the number of punchlines Jeph has written. "OMG! I SHIP IT!" is what one might refer to as low hanging fruit. It has two principle impacts. One, it serves to hat tip the Audience who want a reaction from the gang. Two, it spaces thing such that The Current Fangus Drama reaches a critical point on Friday's strip.
You may say that this can't be right, since we had a Pintsize strip this week. But without the shipping container joke, Yesterday's strip would be Thursday's. Without I SHIP IT and Pintsize, Friday would have occurred Wednesday.
What blows my mind about how you manage to turn something that is basically artist humor into a nefarious plot, is that you seem to feel it was a personal attack. Are you expected to believe? Honestly, no. I really doubt Jeph had what you might believe in mind when he wrote that, or when he decided to get Marten and Claire together.
Given Jeph's anxiety issues (which I don't really know much about, other than they exist) and the douchbaggery of the modern internet (We don't agree with your stance about our hobby. We could have a calm debate. We could have an emotionally charged, namecalling fest. But instead, we'll send death threats to you and any organization that supports you), I'm pretty sure Jeph was a seriously worried about a lot of things. I just don't think your opinion was among them.
Opinions like your's might have been a concern when he introduced Claire as trans (I'm not accusing you of anything). He was going to broach a sensitive topic, and a lot of people might have been upset. They might have felt Jeph was ruining their favorite comic, taken it personally, and destroyed his readership--his livelihood. One might say the same threat existed in making Marten/Claire a thing, but I think the positive response to Claire probably eased his mind.
So, no. No one expects you to believe anything.
But to claim Marten's actions are a departure is a reach and a half. They depart from what you want of Marten, but they are totally consistent with his previous behavior.
Marten sits around until a crisis drops in his lap. When that happens, he either tries to be the voice of reason, or steps back to think about things. THEN tries to be the voice of reason. He's known to be impulsive when drunk. He doggedly pursues anyone he feels an intimate connection to, even though his usual pursuit MO is to be superhumanly passive.
Drunken Marten, impulsively got intimate with Claire. Upon awaking and remembering that, he makes plans to step back and think about it. To some extent he did just that, but possibly not to his usual level. Then he got in contact with Claire and was very reasonable.
Now, keep in mind, Marten has been upset with himself over his passiveness and passive aggression for a fairly long time. After getting the riot act from Faye over Padma, he started practicing guitar. This was meant to signal an effort at change. He, passively, allowed Tai to drag him to a party, but once there he acted on his own initiative to seek out a relationship. He scored, but not in the way he wanted. But the key point: if being passive were still Marten's defining characteristic, the one night stand would never have happened. At the denouement of the ONS arc, Marten tells himself that he has to find meaning in his life. Shortly after, his mother tells him that if he's not sure what risks to take, to try on a bunch of different risks for size.
Shortly after this event, he responds to a snake bite with more decisiveness than the situation called for.
As a result of that he found himself concerned that someone he wasn't interested in was interested in him. This represents 2 minor changes for marten. First, a cute girl might be interested in him, and he don't even consider the option. Despite being kinda lonely and bummed out. Second, he handles it decisively.
Don't believe me?
By the second strip he's seen worrying over it, he's already well convinced it was nothing. In the 3rd, he resolves to deal with it if it's a problem. The 4th is him jumping at the chance to talk to his best friend about it--then being trumped when his best friend turns out to be having a much shittier day than he is. The Final strip is him basically admitting to himself that it wasn't a big deal.
Indecisive Old Marten would have agonized for days over it. Current Marten talked to a couple of friends and resolved the issue in his mind over the course of one afternoon.
So, sure. Marten's behavior is out of character if you ignore everything that's happened since 2100. So just throw out everything Jeph has done with character over the last 2 years and 9 months. Give or take a couple of days.