Cricket is mostly concentrated in India, 1.3 billion people crazy for cricket and thats the main reason why we see such a huge price for media rights of Indian markets. I dont think ICC will be able to generate that much revenue from other regions. Having said that ICC must do something to bring countries like Nepal, Ireland and Netherlands in test format.
There is no doubt India is the biggest market in cricket just because of this now they are taking good advantages as well so here no talking more about this is not positive because now it's time for having some stand for associate countries which are suffering badly specially countries which are having mostly native players they need more intention from ICC about their structure and other things which are important for them to stay in main stream and developed quality but sadly right now ICC or any big country are not interested in this matter which is surely a problem for them.
Countries like Zimbabwe and Kenya are improving something but still not able to do things which are more important due to domestic issues and these things are beyond from ICC here they have to check for themselves and bring better and fair system which could be acceptable for all.
As teams get more opportunity to play against different teams, they keep improving. This suits with all formats of cricket. No market can stand equal to India, to have the attention making schedule for the teams with India will be fair and doesn't disturb the revenue generation. In few years time only few countries will be playing test format cricket.
ICC doesn't encourage more countries, even though they're capable. When more countries get into cricket the control might move hands, and that too a big reason why they doesn't want to take cricket being played by the grown countries of the world.