There is nothing wrong with working an hourly wage. It can actually be beneficial depending on how much you're making and the total number of hours you're putting in during the average workweek.
For example, 1099 freelancers often work an hourly wage when completing assignments for clients. Others work on retainer or charge a flat per-project fee.
Whether an hourly rate works for you largely depends on your preferences and how much the organization is willing to pay you.