Correct us if we're wrong, but we imagine rocking out on a real guitar can be limiting, especially for novice musicians. That cable—no matter how long—could eventually get tangled and trip you up, making you look like a complete tool
Air guitarists on the other hand have no such limitation. Other than the lack of an actual guitar, there's also no cable that could potentially bring them down. Both the transmitter (for the guitar) and the receiver (which plugs into the amp) draw power from a USB port, requiring either two USB ports or an alternating charging routine.
Now we're not really sure how the setup's 2.4Ghz wireless technology affects the sound quality, or there's a transmission delay to affect the guitarist's groove. And at around 20000 yen (or $220, and exclusive of shipping), the USB Wireless Guitar Transmitter and Receiver isn't exactly the cheapest musical accessory.
Yet if you're an aspiring musician and believe a lucrative recording contract's headed your way, then perhaps such an investment will be worth it? Success on the charts usually requires making a good impression anyway, and the last thing you need is some cable messing with your mojo.