Thinking along those lines, I believe Terror Management Theory is a good partial explanation for the cryonics promotion dilemma...
http://en.wikipedia.org/wiki/Terror_management_theory
Unlike other biological species, humans are aware of the inevitability of their own death. Culture diminishes this psychological terror by providing meaning, organization and continuity to people's lives. Compliance with cultural values enhances one's feeling of security and self-esteem, provided that the individual is capable of living in accordance with whatever particular cultural standards apply to him or her. The belief in the rightness of the cultural values and standards creates the conviction necessary to live a reasonable and meaningful life. This cultural worldview provides a base of making sense of the world as stable and orderly, a place where the one gain rests their hopes on symbolic immortality (e.g., fame, having children, legacies of wealth or fortune) or literal immortality (e.g., the promise of a life in an afterworld).
Our cultural world view is a "symbolic protector" between the reality of life and inevitability of death. Because of this men and women strive to have their cultural worldview confirmed by others, thereby receiving the community’s esteem. However, when one’s worldview is threatened by the world view of another, it often results in one’s self-respect being endangered as well. In such a situation people not only endeavour to deny or devalue the importance of others' world views, but try to controvert the ideas and opinions of others which may, as a consequence, escalate into a conflict (ie. religious holy wars). As a result, mortality salience increases stereotypic thinking and intergroup bias between groups.
Two hypotheses have emerged from TMT research; the mortality salience hypothesis and the anxiety-buffer hypothesis. The mortality salience hypothesis says that if cultural worldviews and self-esteem provide protection from the fear of death, then reminding people of the root of that fear will increase the needs of individuals to value their own cultural worldview and self-esteem. The anxiety-buffer hypothesis provides the rationale that self-esteem is a buffer which serves to insulate humans from death. By doing so our self-esteem allows us to deny the susceptibility to a short-term life. Experiments supporting the two hypotheses above have been conducted in the US, Canada, Israel, Japan and the Netherlands. (Williams, Schimel and Gillespie, 2006).
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So, basically any lengthy discussion of death is going to create anxiety and a subsequent need to reinforce one's adherence to cultural norms. This can also heighten antagonism toward ideas that challenge one's worldview. A double whammy against selling cryonics. How can we avoid this trap?