I don't know if his attitude is wrong or not. I really haven't given the question enough thought to answer it either way. Moreover, it shouldn't be an insult to explain how a given ethical attitude can develop whether or not one thinks the view is correct. I'm not sure why you think that would be an insult. Is it because there's a common approach of dismissing the views of those they disagree with by giving psychological explanations for why someone would want to think that? Or is there something more subtle that I'm missing here?
Well perhaps not an insult. But it seems like what you are saying is "This is why I think he might think that but I think he's wrong." If you already think he believes something for a reason you believe is wrong, you don't have a very high opinion of his rationality.
Check out the latest episode of Castle (Headcase) to see Cryonics covered in mainstream fiction in a not entirely terrible manner. The details are not exactly accurate but probably not more inaccurate than similar fictionalised coverage of most other industries. In fact there is one obvious implementation difference that the company in Castle uses which is how things clearly ought to be:
Amulets of Immortality
It is not uncommon for cryonics enthusiasts to make 'immortality' jokes about their ALCOR necklaces but the equivalent on the show make the obvious practical next step. The patients have heart rate monitors with GPS signalers that signal the cryonics company as soon as the patient flatlines. This is just obviously the way things should be and it is regrettable that the market is not yet broad enough for 'obvious' to have been translated into common practice.
Other things to watch out for: