Exploits often feel like pathogens, probably why they share the term virus. If a virus has a high mortality rate, contagion is lower, because it frequently kills the host before it can spread.
Similarly, I think a 'complete device compromise' is much more likely to be identified, prioritized, and patched. The vulnerabilities mentioned here represent the highest severity without an immediately noticeable fallout. Props to the researcher.
P.S. I wonder if the researcher's Russian nationality (assumed from their other post) had any impact on their lack of payout.