Bird was a better rebounder but Dirk is lasting longer.
No one gave props to Dirk recently because of the Mavericks failues in the playoffs in 2006 and 2007. Sports fans seem to remember only the best and worst moments of an athlete (and usually the latter more then the former.) His unbelievable 2006 season and playoffs were written off because of a team collapsing (with the help of one of the few referee calls that directly changed the outcome of a championship) and 2007 first round upset.
And fans like flashy things (dunks, alley-oops) instead of consistency. There's a reason Tim Duncan was never the idol of millions, while lesser talents (Dominique, Barkley, Karl Malone, Iverson) were idolized.
Dirk has been amazingly consistent maybe due to never throwing himself down into the post like a crazy/young Bird did. But still, he'd be one of the top 50 NBA players of all time, possibly the top 30.