You Have Debt
Student loans are one thing, but if you have credit cards, short-term loans, or the dreaded payday loans in your name, chances are that you have been overspending and living beyond your means. Even if you have good credit, if you are carrying balances on your credit cards, you should think twice about owning a home.
This is a dangerous tango. Why? Well, imagine the worst-case scenario. All of a sudden, you're in your lovely home, but you lose your job. Now, your mortgage lender will often work with you—but the creditors? Not so much. In fact, if you fall behind on credit card payments, it could put your home at risk. Creditors may put a lien on your home. Plus, using credit cards to pay for things you cannot afford (if you could, you wouldn't be using credit cards, now would you?) is a really bad habit to be in.
Not only that, if you are saying to me, as you read this, "But it's stuff I really needed that's on the card!" I'll say it again. You cannot afford a house. Home ownership comes with all sorts of expenses—property taxes, homeowner's insurance, furniture, remodeling, plumbing, other maintenance issues. Remember, you have a landlord right now who takes care of all that stuff for you. You'll be responsible if you own the house.