I would not signup for a destructive upload unless I was about to die. But if I was convinced that I was about to die, then I absolutely would.

I don't think that you are missing anything, really. If I uploaded the average transhumanist, and then asked the meatbody (with mind intact) what I should do with the meatbody, they'd say either to go away and leave them alone or to upload them a few more times, please. If I asked them if they were happy to have a copy uploaded, they would say yes. If I asked them if they were disappointed that they were the meatbody version of themselves, they'd say yes. If I asked if the meatbody would now like an immortality treatment, they would say yes. If I asked the uploaded copy if they wanted the meatbody to get the immortality treatment, they would say yes.... I think.

I think that uploading is on the list primarily because there is a lot of skepticism that the original human brain can last much more than ~150 years. Whether or not this skepticism is justified is still an open question.

Uploading may also get a spot on the list because if you can accept a destructive upload, then your surviving self does get (at least theoretically) a much much better life than is likely to be possible on meatEarth.