The lack of control is the real issue.

Being a woman is all well and good, and being a really hot woman is even better, but that's not who you are. You might rail, and maybe sometimes envy the advantages enjoyed by hot women, but you like your life as it was. The threat thrust upon it makes you more aware of the advantages you enjoy, of course. Yet, that's not what really matters. What really, really matters, is you refuse to let anyone dictate who you should be.

The one thing you always hated in your life was losing control. Getting in trouble for your actions, well that's life. Not being able to control your actions? Now that's unacceptable. You told Judy exactly how terrible you thought that feeling was.

And so, you chose to protect yourself and remove that component of the spell. As you told your ex-step-mother, she smiled and remarked that your decision was a little more daring than she'd have expected. She then extends her offer again, but your decision is made, and you refuse. You can tell she's a bit regretful, and she says so. After all, there is no trace in the history of magic of a man induced into the ranks of witches while being, to all purposes of the rules, a woman.