The problem with the abstract seems different from what you describe (I only read the abstract). It looks like a kind of fallacy of gray, arguing for irrelevance of (vast) quantitative improvements by pointing out (supposed) absence of corresponding absolute qualitative change. It's similar to a popular reaction to the idea of life extension: people point out that it's not possible to live "forever", even though this point doesn't make the improvement from 80 to 800 years any less significant. (It's misleading to bite the bullet and start defending possibility of immortality, which is unnecessary for the original point.) This pattern matches most of the goals outlined in the abstract.
That's part of the frustrating thing - there are many parts which do look exactly like the fallacy of grey (thanks for reminding me of the name, I simply couldn't remember it) and he seems to recognize it a bit in some of the later parts like where he describes how a defender of Bostrom might point out that the goal of the fable was to motivate us to eliminate one particularly bad dragon.
But he also took pains to explicitly state at one point his concern with fundamental limits, so anyone who looked at just the abstract or just (all the many) parts that lo...
"Vulnerable Cyborgs: Learning to Live with our Dragons", Mark Coeckelbergh (university); abstract:
Breaking down the potential improvements:
Physical vulnerability
Material and immaterial vulnerability
Bodily vulnerability
Metaphysical vulnerability
Existential and psychological vulnerabilities
Social and emotional vulnerability
Ethical-axiological vulnerability
'Relational vulnerability'/'Conclusion: Heels and dragons'
Before criticizing it, I'd like to point to the introduction where the author lays out his mission: to discuss what problems cannot "in principle" be avoided, what vulnerabilities are "necessary". In other words, he thinks he is laying out fundamental limits, on some level as inexorable and universal as, say, Turing's Halting Theorem.
But he is manifestly doing no such thing! He lists countless 'vulnerabilities' which could easily be circumvented to arbitrary degrees. For example, the computer viruses he puts such stock on: there is no fundamental reason computer viruses must exist. There are many ways they could be eliminated starting from formal static proofs of security and functionality; the only fundamental limit relevant here would be Turing/Rice's theorem, which is applicable only if we wanted to run all possible programs, which we manifestly cannot and do not. Similar points apply to the rest of his software vulnerabilities.
I would also like to single out his 'Metaphysical vulnerability'; physicists, SF authors, and transhumanists have been, for decades, outlining a multitude of models and possibilities for true immortality, ranging from Dyson's eternal intelligences to Tipler's collapse to Omega point to baby blackhole-universes. To appeal to atomism is to already beg the question (why not run intelligence on waves or more exotic forms of existence, why this particle-chauvinism?).
This applies again and again - the author supplies no solid proofs from any field, and apparently lacks the imagination or background to imagine ways to circumvent or dissolve his suggested limits. They may be exotic methods, but they still exist; were the author to reply that to employ such methods would result in intelligences so alien as to no longer be human, then I should accuse him of begging the question on a even larger scale - of defining the human as desirable and, essentially, as that which is compatible with his chosen limits.
Since that question is at the heart of transhumanism, his paper offers nothing of interest to us.