My guess is the mostly the tone and the overly strong conclusion.
The topic is certainly one that is close to home for a lot of LWers and it seems to me we've heard almost all the variations. Then the tone, of a kind of artistic revelatory piece introducing lots of ideas only to dismiss them soon after, seems much more appropriate for a journalistic piece than the kind of deep logical thinking strived for here. Putting arguments in the reader's mouth and talking very patronizingly ("you're a picky one... my friend... this probably isn't going where you expect it to...Algon's recipe for immortality") also doesn't work great in my opinion.
The conclusion is also a point of contention, as people here tend to like calibration and it seems a little too overconfident. Reductionists don't necessarily believe that another copy of you springing into existence later will be the same consciousness, and many readers have commented that they don't. For one example, Scott Aaronson proposes an interesting possibility. Similarly, issues about the universe being infinitely long and infinitely recurring, etc., are very much debatable, with most evidence coming out against you. Then to not treat any of these other possibilities, but whisk through each as if one narrow interpretation did it, seems to me not to be a helpful discussion of the topic so much as a narrow attempt at showing wit.
On the plus side, it's cool that you asked for constructive help and were willing to engage, and I think more research into and consideration of these ideas could lead somewhere good.
This is an exact instance of the point of the post. It is important to assume they are hunting people down, because that's the LCPW and the fact that this trolley problem incorporates using someone who shows up at the hospital is entirely an unnecessary contingent fact.
Pretty sure I remember reading Taleb on this, stating that homicides follow a normal distribution and he accepts Pinker's argument there. He de-couples this from the other kinds of violence, saying that the narrative stretches too wide--specifically warfare should be analyzed separately, since that follows Pareto distributions.