I personaly think the Abe story line just has more story in it. Also becouse its a side of Oddworld that has been more explored then the Stranger one. In AO, we had Muds, sligs, Gluks, Scrabs and Paramites (and a bunch of useless other species). In exoddus and MO they expanded those greatly and gave a wild twist of history to the entire thing. Dozens of new characters, important new locations such as Necrum and its tribes. More depth in the industrial side of things where in AO it was mostly about the native side.
Oddworld just didn't have the chance to do that with Stranger just yet. The Stranger universe has barely been dug out. No real history, no real story line I would dare making a movie around. Ofcourse... I am saying this all with the games in mind. And if they make a movie, it will not keep any of the games in mind. By which I mean, they are not going to skip the Oddysee and Exoddus story's just becouse they already featured in the games. They are going to make a remake out of it, so pretty much anything can happen or be added which will be kind of strange at first. They might add things to the story which wern't originaly there.
In any case I think their better off with a movie about Abe and co, but keep the games focused on Stranger. Stranger has game potential, no movie potential. Abe has both

.