Bluetooth not popular in U.S. b/c of Sprint?

I was wondering what people thought the main reason for the Bluetooth SIG not gaining as much popularity here in the states like it does in European countries. I have thought about this for a while and have come up with a couple of answers possibly. For one, companies like Verizon limit the capabilities of their Bluetooth options. They disable many of the features that normally can be used and make their customers pay for them. Another reason I feel might be contributing to this is that companies such as Sprint and Verizon are still using technology that is based on North American standards and so Bluetooth phones are very rare with these companies. Cingular and T-Mobile have done a good job with incorporating Bluetooth qualities. What do you think?