Depending on what job market you're looking at you may or may not need to graduate.
For example. You want to be a doctor? You better have a freaking diploma or good luck getting hired!
As for my case, I'm going to school for 3D Character animation. Interesting enough, animation companies don't care if you have a diploma or certificate or anything like that. The only thing they care about is the quality of work you do and what you can bring to them. Most people, however, in the industry do go to school to get their feet on the ground and learn the basics. From there, they just practice at home and keep applying for jobs.
So all in all, I don't think it's REQUIRED to graduate depending on the job market. I wish more people would understand this