How would you even go about writing a play in past tense? Are you serious?
The Crimson Petal and the White is written in second person present tense -- and while I understood what the writer was trying to do with it, the device got old quickly and felt way too gimmicky (of course, the book was 800 pages and I only made it about 200 in before I just gave up).
I'm extrapolating information from what I know about written history here, but I would assume that stories are written in past tense as a sense of tradition since originally stories were passed down in an oral traidition. Since the stories were all told about legendary heroes or events of the past, it would only be natural to tell the story in the past.
Additionally, think about anytime you tell an anecdote about something that happened to you -- it's ALWAYS in the past. The reason for this is simple -- how often are you in the middle of telling a story as it's being acted out? This works in drama with a narrator talking, I suppose, as in "She goes to the door..." but otherwise, it feels very forced. At least third person present isn't quite as bad as first person present, since that always makes me think "you're doing this NOW, how are you writing/telling me the story?"
Hi, Shirley Temple Pudding.