Re: Only if you're a Bat fan
She didn't win her right to her costume, she stole it.
and wallys the first flash, there is no hal jordan, hawkgirl and her species are invaders and spies...list goes on. but i see your point. diana earning her costume was always important for the character, but i think her quest to redeem herself in the eyes of her sisters, to show them that patriarchsworld is capable of good, could also have played out pretty well, while still being true to the essence of the character.
all her big name villains aren't actually her villains.
well hades, ares and aresia all had a special backstory/obsession with diana. for a character without a own show to pull from that's fairly decent. hawkgirl only got hawkman(x2) and the shadowthief(and shadowthief had far more connections to the second hawkman). martian manhunter got those aliens from secret origins. it's a teams serie and every explanation for the villains/bakstory etc had to be exactly in the same(or next part of the) episode the villains appeared in. batman didn't get any villains in the whole of jlu!
...stripping away all of her unique powers and character traits nope.
she had to earn her powers late in the series, true, but she had her own character from the get go. again, this is not her "real" new earth self but an abstract interpretation, but you always knew that she was her own character in her own right. and the fact that she represented an archetype, well...flash was the childish comedian, gl the stoic soldier, superman the superhero, batman the outsider(that secretly wants to be part of the team) etc. for a series like this with such an enormous cast(jlu) you have to give the viewer something he knews till you build up the deeper character stuff(only happened to a small degree with diana, i know, but i see where they were coming from).