ICC I think is giving equal opportunity to all the teams. They are considering every team the same considering most of them are not playing a lot of Test cricket nowadays. This may be the reason why they have included all 9 teams in one division.
If they want to give equal opportunity to everyone, then why they placed the three teams (Zimbabwe, Ireland and Afghanistan) in the second division? Why can't they place them with the other nine teams? I find it ridiculous to relegate a promising team such as Afghanistan, without any chance to quality to the first division. Test status should not be permanent. Teams which perform poorly should lose their test status.
The only reason that I can quote for these three teams is that all three teams are very weak teams. They all have not played a lot of cricket as compared to the other nine If compare the last two years. Mind you I am talking about cricket and not any format of cricket.