- Long hair being loose
- Gives enemies something to grab during a fight
- Could get in eyes during acrobatic maneuvers
- Gives hint of secret identity
- Use of color yellow
- Makes her easier to spot in the dark
- Bigger eyeholes
- Reveals more of face, hinting at secret identity
- Less intimidating
- Short cape
- Serves none of the functions of longer cape (protection, intimidation, concealment)
- Still has the downsides of a cape (getting in the way, giving enemies something to grab)
Okay, I guess there are a few good things. Shorter bat ears are more practical, and bigger eyeholes do allow better peripheral vision. But still.
I mean, it’s almost like the character was designed for aesthetic appeal in a fantasy-based visual format, or something.
Brian D. Buckley 
Right now Batgirl is probably saying, “Hey, at least I’m not wearing a one-piece bathing suit like Wonder Woman, and at least I have a proper logo on my chest instead of a cleavage window like Power Girl! And how come I’m BatGIRL when I’m an adult now, and then they gave the BatWOMAN name to somebody else so I’m going to be stuck being a “girl” forever! What’s up with that?”
Yep. And also, probably, “Why does the first half of the Killing Joke movie suck so much? It was worse than the second half, and the second half is where I get shot in the spine.”