I think that I must be the only person who actually purchased an XO, because all of the reasons given for the poor sales are not pointing out the one problem that the OLPC XO had on launch: it was (and still is) sluggish. It is a pain in the ass to use, since doing things like reading PDFs is slow as hell.
My OLPC is sitting in my office unused because, as much as I wanted to use it to read PDFs and browse the web, Sugar is slow and doing things like moving from page-to-page in the reader take a looong time.
On the development side, did the Sugar APIs ever get mature enough that the documentation was stable? Is it really ready for third parties to write software in Sugar without having to worry that large sections of their code will have to change on the nest upgrade? Looking right now at the docs, there are still parts of the code that do not have stable APIs.
How can you take a sluggish device with moving APIs and expect to sell it to countries on a large scale? Will governments really be willing to spend millions of dollars on something that is clearly unfinished design-wise and second-rate?
Microsoft and Intel did not kill the OLPC. The OLPC was enough to kill itself.