me and FE have already started threads about why they dont just destroy the machine to end it all. the simple fact is the game would be toally boring and end without any kind of last boss or interesting time compression and cool ending.
Perhaps. But the simple AND LOGICAL fact is that time is set in stone in FF8, hence destorying it won't help a shred, and since Odine already knows a great deal about time and time compression, he clearly would know as much as to know that destroying it won't help!

For a more indepth account on the role of time, timeloops and fate in FF8, please read the "Time/Ultimecia Plot FAQ" found here:

http://www.gamefaqs.com/console/psx/game/197343.html

It explains why and in what way time is set in stone, thus explaining why destroying the machine wouldn't do anything (it wouldn't destroy time or anything like that, it just wouldm't do anything helpful for Squall and Co, save leaving them with a mess to tidy up!).