Simply because the cost of employing full-time proofreaders 'on the payroll' can be prohibitive (the publishers would have to pay salaries to their proofreaders irrespective of whether there is work for them to do or not!), and it makes economic sense to employ freelancers as and when the need arises. • Having said that, the very large firms may well have 'in-house' proofreader(s), because the publisher would be large enough to 'ride out' any temporary downturn in production - but they would still employ freelancers as well when there is too much work for the in-house proofreader(s) to cope with. More.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.