The worst thing to happen to home automation was companies trying to lock customers into their ecosystem without greater interoperability.
It could be argued Mazda doesn't want to be on the hook for end-user customizations that may potentially jeopardize safety.
Now yes, if a driver modifies his car's code or the results of that code and causes an accident that's on him and not Mazda. But you and I and everyone here all know the media will jump at the chance to plaster sensational headlines for click monies.