It is not unusual to have power generators and power distributors. It is that way in many (developed) countries, even in the USA and Western Europe. In countries with divided system in place, it does not mean that generators cannot have distribution networks and vice versa. The divided system is mainly designed to allow competition, similar as with telephone companies (carrier selection). In many developed countries you can actually select your power supplier (company A, B, C, etc.) and they all bring the power to you via the distribution company.
It works like this:
1) You sign up with power generator
2) You sign up with power distributor to have connection set up
3) The power generator inputs your data into power distributor's system
4) Power generator supplies the electricity to power distributor
5) Power distributor suppliesthe electricity to you
6) Power distributor reads your meter (in most cases this is done electronically) and sends the data to power generator
7) Power generator bills you for the electricity used (variable + fixed fee)
8) Power generator pays the distribution company the "access" fee based on your consumption
In reality, the electricity you physically use may be supplied by your power generator or by other generator (think of it like the sum of all generators supplying the electricity into the distribution grid equaling the sum of all consumption actual and estimated of all the clients in the grid) - So Generator A supplies X1, Generator B supplies X2, etc. and you get billed on generator's terms and conditions, even though the electricity you consume may or may not have been physically delivered by your selected generator.
The similar system goes on with natural gas in many countries.
This si similar to carrier selection in telephone services (your line is owned by your local telco but your long distance and DSL may be provisioned by other companies)
So that is the reason for divided generation and distribution. In the DR it does not make sense, though, because you cannot select your electricity generator.