A person's career choice does tell you something about them, but it's far from the most important thing. I don't think it's valuable as a sole indicator of what sort of person they are or how well you'd get along with them.
As to social status: if someone is willing to befriend another when they have one sort of job but wouldn't be willing to befriend the same person if they had a different sort of job, I think that someone is cheating themselves.