It is not a matter of whether the stepparent is expected to contribute(they have a choice not to contribute just like your parents have a choice not to contribute), but the stepparents income and assets are used and is factored in to assess the financial strength of the household.
When your parents file the financial aid forms, if they are married, the income asset of both your parent and your stepparent in included in the financial aid application.
you quoted a partial answer. the full question and answer is as follows:
It seems that you have no reason that prevent you from completing the financial aid application