I empathize with both Pebble and Apple here. We all understand the issue from Pebble's point of view. For Apple though, security will be lost by allowing one bad actor. To allow an external watch they need to set up a full org for interoperability. Every app/service on the phone or for that matter anywhere in their ecosystem must be designed and potentially reimplemented to allow for outside interaction. That puts a whole new spin on security and privacy requirements. Yeah regulation is one way to force them to prioritize, but outside of that I cannot see them supporting these.