Marcel van der Boom <marcel@hsdev.com> writes:

> I've been wondering about this for a bit. It would make things a bit
> more consistent for me if all properties are in the 'properties'-drawer.
> Or am I missing something here?

The main reason I can think of is that this is historical.  CLOSED: was
invented long before anyone thought about the need for drawers.

Drawers are an added feature that is not needed to be able to make
org-mode useful.  I don't think there should be a requirement for having
a drawer when you mark a task done just to record the CLOSED date.
Having an option to enable this behaviour would be fine with me.

The idea of including timestamps in property drawers is a fairly recent
development in org-mode.