Just my personal reasons for BSN:
I am getting a BSN because I must have it to go on to grad school to be a nurse-midwife.
If I didn't already have a 4 year degree I'd want it in case I needed/wanted it for some other job position (not necessarily nursing... you know how some jobs just require a 4 year degree as an "x" in the block... I'm not agreeing with that kind of policy, just saying I would want it for that reason among many. One of my previous jobs at a children's mentoring agency required a 4 year degree, didn't matter what in or anything...).
As a regular nurse it apparently doesn't make much if any difference though. It really depends on what your future nursing goals are, I think.
If there was a shortage of social workers, they'd only be required to have an associate degree as well
I don't really agree with this idea, there is always a need for teachers and they can't just go get a 2 year degree to meet the shortage needs.
I think that all fields are just requiring more and more formal education. Soon you'll have to go to college to flip burgers at McDonald's.