OK, I've just enabled this one, it can be indeed a useful function. If it will cause any problems I can always revert it.
There already was a discussion regarding this matter a long time ago.
It is configured now to allow editing during 24 hours from initial posting. (even this is too much IMHO). So you have 24 hours to correct mistakes you might find or change your mind about something. This way the "edit" function serves it's purpose.
If you come back a week or a month later to edit your original post you just confuse people. In this case you better double-post.