You're quite right Helgard. This is essentially exactly what Erasmus is saying. His criticism is particularly around the failure of organisations (public and private) to upgrade, thereby placing themselves and the public at risk, and he has also raised what RussWood is saying below - the prohibitive cost of data, which can discourage people from downloading upgrades even if the upgrades are free. I think I mentioned in the article that he has suggested ISPs get on board with incentivising the downloading of upgrades, but that might be aiming a bit high! 
Regarding the modest amount of money made - part of it was, I think, the many mistakes made by the hackers, but these are mistakes that have been corrected in the newer ransomware. There was a great article, in the Washington Post I think, that analysed the reasons for the piffling payoff - I don't have the link handy but if you google it you will probably find it fairly easily. Thanks for the comment.