The key points of Barbara's past are that she is the daughter of Police Commissioner Jim Gordon (though I don't think he is the Commissioner anymore, at least before the reboot). She was one of Batman's sidekicks, along with Robin, before the Joker shot her (as Barbara Gordon, unaware of her identity as Batgirl) and caused severe spinal cord damage. With her ability to walk taken away from her, Barbara reinvented herself as Oracle, an amazing computer hacker and information hub for not only Batman, but to a large number of heroes including the Justice League.
As Batgirl, Barbara belonged to a fairly large club at DC, that of the sidekicks. Robin, Kid Flash, Aqualad, Wonder Girl, Speedy...DC is big on sidekicks and legacy characters. She also belonged to the female off-shoot of a male character club; Aquagirl, Supergirl, Jesse Quick, Jade, and so forth.
From her wheelchair Barbara made a difference. A huge one. She was no longer the one out there preventing muggings and saving the world, but she held a pivotal role supporting those who did. She saved a lot more lives from her chair than wearing her cape.
Now I am certainly not equating the fictional exploits of Barbara Gordon with the real-world accomplishments of Rick Hansen, but my point is that a disabled character is not only inspirational to those similarly afflicted, but to those who are able-bodied as well. A character like Barbara also teaches acceptance and inclusion of those who are different.