Because being Batgirl doesn't require fancy gadgets, or an awesome Batmobile.
Notice the art, the style, the mask! Batgirl! Anyway.. Like guts (but not literal guts, which are also on the inside, but toughness! Yes, everyone's favorite female crimefighter, teaching Batman how to still look good while kicking criminal butt. No, being Batgirl is about what's inside, about delivering justice no matter the odds.