Loved Seveneves, but it is one of the best examples of his not having an ending.

While some other of his books do not have the most satisfying endings, Seveneves was the only one where it seemed like he simply gave up trying when writing the last 5%. Compared to the previous sections, the end just seemed like it had no effort put into it. Everything after the death of the doc just seemed abrupt and clumsy. It seemed jarring compared to how much care he seemed to put into the detail of the earlier passages.

I love the world building of the 2nd half, and would argue it doesn't need a clear ending. Your imagination gets to fill in the blanks.

I stopped reading Seveneves after we zoom forward to the future and stuff got weird, a bit too weird for my suspension of disbelief. Does it get back to more hard sci-fi stuff or remain as something which, to me, felt more like a sci-fantasy hybrid?

Oddly enough I love books like Dune, but the dramatic change in Seveneves was just too jarring for me to continue enjoying it.

I think it's pretty clear from the comments here that there are those of us who just can't really buy the jump-cut and there are those who can.

I would argue the sci-fi indeed gets so hard, that it becomes soft again by nature. The technology falls away from the focus, as it should, but it is still very much there.

I was listening to it on audio book and after the "5000 years later" I paused it and didn't pick it back up for a long while. Slogged through the rest. Won't read/listen to it again. The ending was ok. This was my first Stephenson book. Not going to do more.

I think Seveneves would have worked better for me had the jump cut been a significantly shorter period of time, had there been a shorter more hand-wavy epilogue that didn't get into all the detail, and (frankly) had it thrown out a lot of the last part of the novel. But I'm not Neal Stephenson either.

I hear people say that a lot but I don't get it. I experienced it as a hopeless, depressing slog, where things just got worse and worse. But fortunately I wasn't attached to the characters so it wasn't so bad watching them all suffer.

I agree with you, you are not alone. Seveneves had some great ideas, but he spent way too much time on the science and put almost nothing into character development. The characters were so flat, the interactions and motivations were lacking, and ultimately I just didn't care about any of them. I can't recall a single character from Seveneves but while I can't remember all their names I very much do remember the characters from Snow Crash.