Women can be that way. Actually, people can be this way, it's just that your significant other is in your life pretty intensely so the inconsistencies are more glaring. A lot depends on whether this is what your whole relationship is like, or whether this is just one issue that crops up from time to time and otherwise things are good.
I've had a little bit of this with my wife, mostly when money-related stuff is at stake. When I go off to band practice and there aren't gigs in sight, she may complain that my band thing isn't making any money. When I'm off to a paying gig and the band is busy, she may complain that I'm not home more. Or with gear purchases - she worries about money, and honestly I AM the bigger spender of the two of us. When I would buy something, she'd say I should save up over time to buy it, even gave me a piggy bank for a birthday to make the point. When I saved up for six months and then bought a new bass, she said the piggy bank was a joke and she didn't expect me to actually use it. Or another time she said if I wanted to buy something, I should sell something else to raise the money for it. So I started selling my books over amazon, and bought stuff with the money... and she was still unhappy about the new music gear in the house. She just doesn't like me buying stuff, period.
Is it a pain? Yes. But it's just a particular anxious spot for her, and the marriage is strong in spite of little things like that. And, at the bottom line, she understands that a guy needs to get out of the house and go hunting or go bowling or something, that it helps him come home to be a better husband and that for me, band is that something. She's supportive on the whole. Really, the complaining is just a (rather annoying) way of saying she loves me and wants me around more. I can cope.