You might find it odd that he would be against land swaps, seeing as how Palestinian negotiators have been in favor of such a deal going back to Arafat. At least he is actually a Palestinian and will suffer the consequences of his own shortsightedness, but it's still pretty informative that an ivory tower 'activist' will condemn his own people to suffer for his own ideology.
So why doesn't Jabarin want there to be land swaps? I could quote him but he goes on forever in typical lawfare language, so here is the basic reasons:
1. It means the "illegal" settlements are allowed to remain (oh no)!
2. If one land swap occurs, more will and the Palestinians will end up with less land (somehow).
3. "East Jerusalem" is "Palestinian territory" too, and that should be included.
4. Palestinians living in Israel (i.e. Israelis) will cease to be Israelis and will therefore "lose" their "right" to freely go into Israel whenever they want. Of course, Israeli settlers will lose their "right" to go into Palestine but apparently he isn't so concerned about that.
After this he just goes into the usual whining about how unfair it is the Israel is so much stronger than the Palestinians and can impose their will on them accordingly, and that only a "legal foundation" can be used toe resolve these issues. I'd love to know where his legal foundation was when Hamas was raining rockets on Israeli cities.
But anyway going back to his laundry list of complaints, I can't see any reason why land swaps should be "off the table" except for #1, which again I am not that sympathetic to. Even though as Jabarin claims that (pretty much) everyone considers the settlements to be illegal he should also know that (pretty much) everyone also agrees that ethnically cleansing hundreds of thousands of people just isn't going to happen. Including the negotiators that he loves so much in the PA. You can cling to your ideals all that you like but in the real world the settlements are not going anywhere and you can either accept that and continue to suffer or choose a different path.
The top favorited comment at this point sums up Jabarin's point of view very well:
Indeed he is. And the Huffington Post readership are ready to cheer him on as well.
Update: According to the Shin Bet, Jabarin is a senior member of the Popular Front for the Liberation of Palestine, an internationally recognized terrorist organization. The Huffington Post has got a lot of scummy people to blog for it, but I'm pretty sure this is the first time they've had an actual terrorist writing articles for them.