Why do you think in our region the Open Source products are not mostly used?

First, it has to do with expertise and knowledge of Open Source projects out there.  The lack of knowledge about the mere existence of such projects does not help their use.

Secondly, it has to do with marketing and politics where local companies and governments sign deals with the IT giants in the market (Microsoft, Oracle, IBM, etc.). This fact unfortunately is a big roadblocker to Open Source software to being introduced in the region.

Lastly, there is no official support for open source projects which pushes local companies from using there. Although most of the active open source projects are backed by large communities with active forums where support questions are exchanged. The larger projects are even backed up with paid support by a seprate registered company like the Spring framework for instance.