Good Question
It's not except in Grondine's mind. I haven't seen any space experts or advocates take this stance. David Morrison who helped pioneer evaluation of the impact risk is a proponant of the lifeboat approach. Despite Grondines conflict of interest claims, the majority of impact experts still assess the risk similarly to Morrison. The recent UK report basically validated the risk assessment of the previous US sponsored reports. The key difference was a lower limit on tolerable risk and recommendations to set a lower size limit for detection goals.
Regards,
Mark
