My guess for some if them is they might have needed the money real bad. I'm not sure how sales of account work.
I think they need the money badly because selling an own account is not easy because the one who will suffer is those buyers of that account because he/she doesn't know what would be the process of earning BTC because the real owner of that account is not himself 
Yup, even with a high rank account, someone still needs to read a lot and learn how to make use of that account to produce the money they want ~
For you Because you need money
For hackers need to scam many
For business men need to promo products
For hackers need to scam many
For business men need to promo products
I'm absolutely agree mate ~