I don't know how the situation for jobs in the US is but in Italy, where I had my experience, the people that do this job don't do it because it's their dream job but because they have bills to pay and finding "something better" is not always easy.
Part of accepting capitalism to such an extent as HN is a brutal lack of empathy.
Still, getting a job where you are paid with my money to harass me is not the way to get on my good side. Either way, I never take those calls, and never take anonymous calls either, unless I'm looking for a job.
Beside, that kind of behavior from a company here (in France at least, and probably most of Europe) is probably illegal.