Why doesn't third party cables work on the Apple ipod

and told nobody about it.

And even better, they changed the firmware of some devices to drop support for the old standard. IOS 4 on the iPhone caused lots of automobile iPhone interface kits to suddenly stop working (such as mine). So I had a nice Griffin TuneFlex Aux which is now useless, as iPhone music would not play on my stereo anymore. So I had to shell out $50 for a new Griffin TuneFlex Aux.
To answer your connection, specifically:
http://en.wikipedia.org/wiki/Dock_Connector

"Originally, the Apple dock connector carried USB, FireWire, some controls and line-level audio outputs. As the iPod evolved, so did the signals in the dock connector. Video was added to the connector. FireWire was phased out of the iPods, which led to a discontinuity in usage of the dock connector. Older implementations of the dock connector may have been using the FireWire power pin to supply power, and cannot charge later iPods and iPhones or the iPad, requiring an after market adapter to allow charging."

Thus there are at least four or five different pinouts of iPhone/iPod dock cables out there. If you have a third party cable, it may be an older version, so it's not the same.

You would think there would be some standards, or even some markings on the cable to specify how it's pinned-out, but nooooooooo, that would not be very apple-like.

You just have to buy zee apple product and you vil like zee apple product.