Probably because it was unreliable, as there is no definitive way to detect
the difference between an open tray, and a closed tray with no disk in (you
CAN detect a closed tray if a disc is present)...
The damn Windows API responsible for this just doesn't provide that
information so all the programmers can really work with is detecting the
media change event when the tray is closed, and if the tray is empty when
closed, that even doesn't get fired...
I spent ages researching this a few months ago and did write a little
program to open/close the tray as a toggle, but again it was unreliable as
it couldn't detect the state of the drive when the program was started
unless a disc was in the drive, and could lose track even more if you
opened/closed the tray manually...
Lorne