How come every gen has one dominant console over the others?

[UltimateUnknown]

Kasz216 said:

bananaking21 said:
how on earth is 4th a gen with a highly dominant console? its just 9m between snes and the genesis.

I'm seeing ~20 Million based on the VGchartz numbers.  

29 Million vs 49 Million.

 

Do you have different numbers?

You're right. Genesis was 29 mil, I wrote it wrong as 39 which might have caused some confusion.

I've corrected it now.