The Conflict Between Time Travel and the Macguffin

When I used time travel in the book Schlock Mercenary Resident Mad Scientist a lot of people complained that I was using it as a Macguffin just to save the day. Time Travel is a sticky thing for a writer to get involved in because there's such a history of it. So many aspects of time travel have been covered that it's very hard to break new ground. And so doing anything new with time travel is so hard.