Father Alexander Schmemann wrote about this -- how the 3 year seminary as a "graduate school" is a very western concept that the Orthodox Church in the west has adopted..... historically, a boy growing up in an Orthodox town would be seen for 10 or 20 years, and in essence God would choose him to become the priest (the leader of the local Christian community).
It's not this simple anymore, since there are hardly any "Orthodox towns" in the West.
A seminary degree does not equal ordination, and NOT having a seminary degree does not preclude one from being ordained, either. In my parish, we just had a deacon ordained who completed the OCA's "late vocations program" -- geared toward Orthodox men older in life with families and prior careers who want to serve their church. As I understand it, it's more or less independent study. From what my priest was saying, there are still grueling exams.
Plus, the idea that you can learn in 3 years in grad school everything you need to know to be a priest is insane (similar to how inadequate I felt after 4 years of medical school -- I still felt like I knew nothing! Practical experience is crucial!). It's a westernized concept that we Orthodox in the west have adopted.
On another topic -- the "right" to become a priest.... when I commented above that some Western Christians regularly claim "rights" to be priests, I had in mind the militants (mostly "disadvantaged minorities," women, gays, etc.) who clamor about this, and who many churches (Anglican, Lutheran, Methodist, etc.) have given in to. Those people became ministers and priests because of their complaining that they had a "right" to do so. You even see this in Roman Catholicism as well -- women claiming a "right" to be parish priests. As I stated above, there is no such "right" out there -- God chooses who He wants to be priests.