Come one, I know all that. Everyday I sit with three other sys admins, and I'm sure that particular problem would baffle them as well (for a while). That _I_ happened know what to do, was because I googled for 1 minute (the "think" I was speaking of, two posts ago), and I've been there before. I haven't used lilo for years though, precisely because of it being much less user friendly than grub. What you fail to see is that pulling a boot disk will render ANY system useless, so just don't do that or think (but you can always easily revert the situation and then think, on your old configuration).
And I'll just repeat myself again: yes, it _would_ be nice if a system could help you with a missing boot disk, but obviously hardware just doesn't do that. You should understand that the hypothetical programming -that helps- you speak of would originate from the BIOS. Or, better still: from the embedded linux on your motherboard. But I just haven't seen anything like that before, have you?
It is a nice idea, by the way. I'm sure we'll be seeing that in years to come.