Verizon knows that if an upgrade goes bad, 99% of the people won't say "My Motorola phone doesn't work anymore", they will say "My VERIZON phone don't work no mo!" Verizon has a corporate image to uphold, and they want to make sure their business partners are aware of that. People jump from carrier to carrier all the time. I went from Cricket, to T-Mobile, to Verizon myself. Verizon doesn't want to loose revenue and potential revenue based on a failed upgrade by a manufacturer.