It is the fact that most customers who insist upon having patch panels for voice and data do so with the silly thought that they will be able to place their own connections.
That's reason number one. Reason number two is the silly thought that any cable or jack can be used for either voice or data. Now you have problems breaking out pairs at either end as is normal for voice. You also have the problem of 6 position plugs damaging the pins of 8 position jacks as well as users not knowing which jack is voice and which is data.
Only in the minds of CGs does this make sense.
-Hal
