As we all know the internet is tubes not trucks.
So now whoever owns the tubes wants to be free and charge based on what the tubes carry.
I remember when i got charged depending on how many bits i sucked from the tubes and i quite liked when i got charged flat rate. Thus if the owners of the tubes didn't have a monopoly i would imagine that the market will decide in favor of the flat rate.
Now they want to charge me based on how the bits are arranged? I see no reason whatsoever for that. 100111010 costs exactly as much as 010110111 to transport to me.