That's a question I've asked AMB-USA several times. The only explainable reason they could give was if the software is written for the Linux OS the USB would be useless. In fact they called me for a survey of my likes and dislikes of the AMBrc3, that issue of no USB was one of just a couple of dislikes. One reason I like the USB so much is that the decoder can then be powered through the computer. If you’re using a laptop and have a power failure you have the battery of the laptop as a UPS!