1. This doesn't appear to be a falsifiable position with respect to being overly conservative. Any action that results in the hospitals not being overwhelmed will be taken as somehow likely causing the hospitals not to be overwhelmed. It's not clear by this logic how hospital capacities are ever chosen given various uncertainties in the environment.
2. It commits a status quo bias. Only the risks of deviating from shelter in place are considered. On the one hand we have a virus with a CFR of around 0.5% with fairly well understood vulnerabilities to various parts of the population. On the other we have a completely unprecedented shutdown triggering a 2T spending package and causing record unemployment, with an unknown end goal. Is the risk of continuing down this path somehow less than the risks to the hospitals based on our knowledge of disease?