We don't call that productive where I work, but I'll accept your definition. Nevertheless, its pretty telling that you would support the practice of using people's private telephone to exercise deceptive and coercive selling practices on people that just don't want to be bothered.
I honestly don't give a flying rat's backside what the annual report of these companies say. They are a public nuisance. I suppose that thieves and robbers have quite an impressive annual report as well. They also are a public nuisance. Both tend to separate people from their hard earned cash and generally give that person nothing of value in return.
I could actually give you quite a list of things young people did before telemarketing... ushers at movie theatres, pumping gas and cleaning windshields at gas stations, carrying groceries home from supermarkets in wagons, summer jobs at US Steel that more than paid for college so parents did not need to second mortgage the house, etc. Lots of things that aren't around any more.
There's a whole want-ad section in the sunday paper that is full of jobs that need filling. Most of these jobs don't involve harassing people in their homes.
Just because people can do other jobs doesn't mean that telemarketing wasn't a decent position for some people. Suppose they would like to have another choice than slinging burgers at Mickey D's? You find them annoying, but they are employed people, young, middle-aged, and elderly... all making a buck and spending a buck... paying taxes... contributing to our capitalistic society.
Hit-men are employed people too, as are drug runners. But both share a common thread with the telemarketer - they are a burden on the innocent people that want nothing better than to have peace and quiet in their own homes. I don't desire to contribute to the employment of any of those groups.
Paid telephonic harassment is in no way 'decent.'