Why is 21st time travel into the past and not the future?

[Thom]

I am currently reading 11/22/63 by Stephen King and love it. He has adopted a theme that seems to be very popular this millennium; time travel (thank God it isn’t about people with long, pointed canine teeth with an unquenchable thirst). This isn’t really a new theme as many well known (and lesser known) authors of the latter 19th and early 20th Centuries used it. The big difference is (with the exception of The Prince and the Pauper by Mark Twain) that characters moved from the present to the future and now all move in the opposite direction. One could almost conclude that this means that we’ve past our prime but I would rather take the more optimistic road and say the past is safer to portray than the future. Few (if any) authors got the future right. Some were admittedly, even scarily close but alas no cigar! Why do you think time travel is now stuck in reverse?