Speaking from over 20 years of marital experience, women are constantly "testing" men .... I don't think that a particular reason exists ... it's just the way it is ... kind of like how guys don't like to ask for directions, etc.
You're being tested and you're being measured on your response.
So, I conferred with my wife to ensure that my logic was sound:
Allow me to translate: She doesn't want you to go but she wants it to be your idea.
If it were her idea, then you might resent her for asking you not to do something you love to do.
If it is your idea, then she gets what she wants without guilt.
Just a thought ... why don't you take her with you? You haul 70% of the combined weight, pack a surprise bota of wine, some candles, some cheese, and a sleeping bag for two. Cut down the miles, take her to camp near a waterfall or hot springs, and turn it into a romantic adventure.
Your reasoning could be something like: " I so want to be with the person I love most in this world and enjoy the place I love most in this world."
If she'll go with ... the cat will be safe!