2-year Universities: Who made up the rule that we have to attend college for 4 years?
Tertiary education does take a hell of a long time in the US. In my field, and in my generation, most UK students got their PhDs around 24-25 years of age; for the US students it was more like 27-28. Yes, if that is a real effect that would definitely be a problem.
I can think of two factors that may be affecting this (I have no data):
1. The level of the student arriving at college. Yes you can probably get a professional degree in 2 years with no holiday breaks, provided your college doesn't have to teach you basics.
2. The fact that US colleges cost so much money potentially create a vicious cycle - you need a job to pay for college, which means you need enough spare hours in which to work, which means you have to space out your courses, which means you need more money etc etc.
I would be certainly interested in views from US graduates as to why they feel it takes so long.