I do agree in that war has many problems, heck almost everyone agrees. War is likely the most critical problem in Stellaris, but is exactly why has to be worked with extreme care.
I think they chose to work in this with internal affairs in this patch because it was a feature of the game that needed work and it was simpler to solve, this way they would get money(expansion) and mantain the game alive long enough, while trying to find good ideas/ways to work in war(space and ground), even if not fully focused. I mean they probably want to rework war from scratch, like they did with some mechanics in this patch. It is not easy to find a good way to improve war in all aspects in theory, and depending from what it is, it becomes impossible/inviable to program.
My point is, even if I don't like war as it is, I think it is a good idea that it is taked slow considering that is a really sensitive matter(you can see in the forums how war always has several divergent opinions).