No, I wouldn't judge anyone by their present occupation.
One never knows how they ended up where they are. Maybe they were laid off their job and couldn't find another one in their field.
Everyone has what I call "a story" that explains why they are "there".
It's possible they are going to school and working this job because the hours are flexible. In other instances their "dream" may be to be in show business. Just about every major "star" at some point was a waiter/waitress, valet, taxi driver, telemarketer, or whatever.
Essentially this job is out of necessity and not their "goal".
Last but not least there are people who score high on IQ tests but lack ambition, drive, and determination.
They take whatever comes (easy) or is least stressful for (them).
Ultimately if someone (enjoys) what they do for a living they're successful!
There have been doctors who quit practicing medicine because their heart wasn't in it. Michael Crichton was one such doctor who went on to become an screenwriter and bestselling author. He wrote "Jurassic Park". Intelligence is finding a way to live life on your terms.