This is certainly one "drawback", depending on your perspective, and certainly a cost more of an ORM and how they tend to work than a runtime environment. You'd have a similar issue, for example, in Go if you want to lazy load a property (however there you can't await a goroutine).

Long story short, this drawback tends to be primarily based on experience of the overall system. Coming from traditional rails/django/etc will make these constructs seem awkward.