the default is smart
Looking at the systems that are supported, it makes the greatest sense to have the safest failure mode as default. If fault tolerance is available, that can be handled in the entry but, it makes sense but to assume. Having that capability built into the default adds more complexity and reduces support for systems that are not tolerant of a missing mount.
Does indeed sound likely to be an fstab issue, unless system services are being used in a really weird way.