This is a common practice by manufacturers to say if the product is not registered its warranty is not valid. The laws in the US prevent a manufacturer from denying warranty coverage to original purchasers that can provide proof of purchase. Regardless if the product was registered or not. However registering with the manufacturer makes things a whole lot easier for everyone and can allow them to contact you in the event of some sort of recall or whatever.
Now I'm not at all saying JC or any of the other awesome turbine manufactures do or have caused any issues. Just something Id like to share