I used to be one. But then so many people were using Whatsapp I started using that. Fewer and fewer people were using BBM. Even fewer still were the number of people who used BBM exclusively. Now I don't think I'll miss BBM at all and as a result I'm looking to Android for my next phone.
Or the opposite. Do you retain more people through fear and lock in, or do you gain more by being open and transparent?
When one of your last advantages is from lock-in, giving up that lock-in seems… risky, at the very least.
Edit: Not that hanging onto it would help them either.