Voltage Dividers, High Power resistors
Resistor ladder dividers are no good as a voltage source for all but very specific cases. The reason for this is twofold: they are very inneficient, and they depend on the load connected to them.

To give you an example: Say we want to deliver 6W at 6V. Working from 48V DC, this would mean that we need 1 Amp to flow through the voltage divider (at least!). On of the resistors will have 48V-6V across it, which means it will be dissipating at least 32W. Your powersupply has a best-case efficiency of 12.5%!

In addition, the output voltage is sensitive to changes in load. If your load increases, the output voltage of the divider will decrease. How much depends on the values of the divider resistors. The higher the stability, the lower the efficiency (and it can already be no more than 12.5% efficient in our example!)