A coworker of mine was recently declined for a Chase Sapphire card. I know what she makes, as a public servant, and I know what her husband makes, too, since I hired him. They are clearing ~$60,000 a year disposable (as in, after taxes, student loan payments, housing expenses, etc.) She was a practicing attorney in New York and Munich for three years, has tenure at a position where it's nearly impossible to fire her, and is a married, 30 year old woman.
She suspects it's because she's only ever had one credit card, and she never increased the $2000 limit. I am sure she's right, but that seems like an awfully narrow risk for Chase.