That's kind of begging the question. I wouldn't consider her that iconic. Wonder Woman and Supergirl seem to be far more popular, and consistently used. "Batgirl" seems to be more of an interchangeable ID over the years. Arguably Barbara Gordon has become more iconic in our 21st century technological environment as Oracle than she ever was as Batgirl. And a more interesting character as well.
I'd say the character beyond the TV show is "iconic," if she is iconic, because she's a female version of the iconic Batman.
As for the TV Batgirl's appeal... *shrug* while there were other reasons for the show's cancellation after three years, Ms. Craig's appeal wasn't sufficient to overcome them. The show didn't need a third hero, particularly in the half-hour 3rd season format. I think she's popular for the same reason Lynda Carter's Wonder Woman is: can kick butt (bringing in female audience members), tight costume, attractive woman, often ends up in submissive situations that means she needs a man to help her (keeping the males).
If you compare the 60s TV Batgirl to iconic characters of the period like Wonder Woman and Emma Peel, I'd dismiss Batgirl as a very distant third.
Edited on 06/03/2011 1:40pm