Please understand the subject you're talking about before discussing it as almost all of your information is incorrect.
At U of Phoenix, there is no difference between full and part time. You take only one class at a time and each class lasts for 5 only weeks total. That's right, that whole load was ONLY ONE CLASS AT A TIME. Additionally, I WAS unemployed at the time and was still barely able to keep up. I was mentioning the full time employment bit in response to their (omnipresent) advertising that repeatedly describes how you can complete a degree and work full time.
Second, I was in their IT program, not an arts program. That did include some management classes on the course list, however the classes I took were more oriented to networking and such.
Third, US colleges are the same way. Note I stated 12 CREDITS, not 12 classes. Each class is a higher or lower number of credits depending on its course load and difficulty.