There are generally assumptions people make when they get married that should have been worked out before marriage. But the reality is that few people do work out details such as one plans to move to New York within two years, and never mentioned it. And the other lived in New York, and hated it so bad, they said they'd never go back.
On first glance, it may seem "My wife is being a wet blanket, since she doesn't support my dreams?"
If you were a famous writer, with a six or seven figure income, she'd support your habbit. The questions that need to be asked are practical. 1) Do you make enough money to support a family? Is your writing preventing you from getting a job that will help you support your family?
If you've worked as a writer, and you are between jobs, then that's a different issue, because you've proven you can support yourself and your family. But if you've never made an income, and you are just planning to hit the writer's lottery, and expect your wife to wait around until you do, then you are being unrealistic.
Never give up on your dream, but you have to put your dreams in perspective, and make priorities. Vince Lombardi was a successful pro football coach. He had a list, and somewhat demanded his players adhere to it (this was in the sixties) God, family, football, in that order. Obvious today, people would look at that and you'd have the ACLU at his doorsteps.
However, if you look at the concept, generally a person has to make a priorities list. In my mind, if wife and children are down around numbers 3 and 4, there will be problems in the relationship.
It's not the words you say, "I love you...yes, I'm commited to you..." that matter. It's the actions that confirm those words. "Yes, you are number one in my life, but my mother comes first," won't cut it. If you say you love your wife more than your mother, and your boat, and the guys, but you spend fifteen minutes with your wife, and eighty hours with the boat, your mother and the guys, your words mean nothing.
So, question one. Have you taken care of the practical end of being a husband, which includes helping put bread on the table, or do you expect your wife to hold down jobs while you work on the computer? If you have a great job, and this is a dream, then you can work out a compromise.
Two, how much time do you spend with your wife? Does she get quality time or left-overs, when you are tired and exhausted. If you are working a full time job, and a great bread-winner, and you are spending 4 hours a day on the computer, then again, your wife will feel cheated, because your actions say, "Take a back seat, this is more important."
Hey, this may seem old school, but love is a sacrifice.
So, I guess I'm saying, we don't have enough information to answer your question, whether its you, or your wife, or both that have unreasonable expectations? But my long answer will give you a clue where this is going.