Part of the problem is that lies get spun a in whole lot less time & effort than the job of debunking them requires.
Yep, the damage is already done and media scum have infinitely more power to smear and denigrate than they do to right the wrong, even if they really cared to do so. The hype is on page A1 above the fold, the retraction page is on A16 in the bottom corner, the size of a postage stamp.