>>I really find it hard to believe that that dialog is only tied to the OS getting a Ctrl-Alt-Del keystroke sequence.
>
>(yeah, I know, this one's a bit on the moldy side) I've been hacking at this on and off for the last week (hard to do, since I only run Win9x on multi-boot at home), and I can't figure out how to get it with anything other than a three-fingered salute. As far as I can tell, getting to it programatically isn't going to happen.

In NT 3.51 you can get it with Ctrl-Esc.

This is pure speculation, but maybe access to the Task Manager was "secured" in NT4 to help it get its C2 security certification, and the practice carried forward through all later W32 OSs.

OTOH, NT4 was released after W95... but probably NT4 was in development longer.