Neither of these two. It is another career option where one can join, excel and lead - or - join, be average and pass life in another job - or - join, be at lower end and crib for whole life.
Most of the times people - politicians included, denounce BPO job because these make one to work at night - but why don't they complain similarly about policemen, doctors & nurses, pilots, drivers...and other traditional jobs where working at night was required?
This is service sector guys, you have to work in the shifts of the customers - not of your own.
There could be sporadic studies too about x% increase in health and lifestyle diseases - but don't you think they this thing would have happened in case of any other while-collar, sedentary job too?
Most of people complain about BPO guys because they themselves are looser and/or can't see somebody who was a non-traditional-top-rated-skills person (i.e.no doc/eng/lawer etc) excelling wonderfully in life.