Maybe it is done this way to allow developpers to reorder their assignations without having to bother to put a comma on each end of line except the last one.
Something like:
KarmaComa theThing = new KarmaComa() {
A = 1,
B = "Foo",
};
that could be easily refactored to:
KarmaComa theThing = new KarmaComa() {
B = "Foo",
A = 1,
};
by simply drag-and-dropping the line.
But this is just a guess.