Momo_White Shinigami
To be honest, Madoka wasn't bad until it's last two episodes. The way they try to logically explain how Madoka should be the strongest-when it should be Homura-and how Madoka treats the Magical Girls at the end makes me want to smack Orabuchi. Other than that, the show wasn't bad. The characters were a little flat, but other than those two episodes, it was alright.
Really? The ending made perfect sense to me, and didn't even feel rushed.
Eflow Nivek
Her wish was to erase witches before they were born which means that a magical girl must go through the corruption of their soul-gem before she can help them. Plus, they're already liches anyway they're already dead.
However, why she didn't wish to re-write entropy is another question. Assuming holding off entropy is what Kyubey really wanted.
(captcha: do you believe in miracles?)
They're compared to liches because they have phylacteries. They're not actually dead, either spiritually or biologically.
Momo_White Shinigami
You are right on where Madoka jumps in, but the thing of it is, she doesn't have to kill them or deplete their Soul Gems. She could just make a universe where the Soul Gems were just purified, have the girls just die by demons/Witches, and have entropy be cured by the deaths of those girls.
It's easy to claim after the fact that a Wish (capital 'W') should have been phrased better than it was. Easy for the
audience. After the fact. That a middle school girl came up with a solution as good as she did should be impressive enough, and personally I did not expect her solution to even be allowed--for one thing, it proved that the Incubators can't actually reject Wishes.
We can speculate that she could have made a better Wish, but it's just speculation in the end. There are limits to how great a Wish can be--this was stated. It's dependent on the potential power of the Puella Magi, which has something to do with potential effect on history, which was increased in Madoka's case by the repeated world jumping. This wasn't a random story element--it was necessary that it be focused on Madoka and not Homura to lead into Homura's final despair as Kyubey explained the facts to her. Furthermore, the specifics of the Wish did not state the method by which it would be accomplished, and yet it still resulted in the negative energy/despair/corruption of all Puella Magi throughout history being concentrated into Madoka. From this we could similarly speculate that had she wished for unlimited purification of all Puella Magi that she would surpass her own limits, and it's a safe bet that wishing for a safe, clean, convenient end to entropy would have outright failed.
Not to mention, a safe, clean, convenient ending would have gone against the atmosphere and intents of the story, and would have been boring.