could be wrong but i can't remember him being out for any long stretch before his major injury, by which point he'd already sealed his United Legend status, so you can't blame the club for keeping him on their books and showing hope and faith that he could return, if United would have tried to offload him there would have been an outcry from the fans anyway and rightly so...
Ole is a legend for all the reasons kai and microdot have already pointed out and many more also...
i hope the 20legend banner hangs from the Stretford End for all eternity...