I mean, if they are unique to devices for which they make sense (i.e. phones) than webOS' APIs seem to be just as standard.
What I was pointing out is that EnyoJS or WebOS or Tizen (afaik) do not make any effort at such portability. Sending a SMS makes as much sense on a WebOS-based device as on an iPhone, an Android smartphone or any other platform. This is one of the key differences between initiatives such as WebOS, Windows 8 or, to a lesser extent, Chrome OS on one side and Firefox OS on the other side. While these OSes offer the features of HTML 5 and some proprietary, non-standardized, non-portable extensions APIs for taking advantage of platform-specific capabilities, Firefox + Firefox OS push to make these capabilities 1/ accessible on all platforms where they makes sense; 2/ standardized so that other browser or os vendors can implement them as they see fit.
The difference is subtle but meaningful. This is the difference between "come and program for my silo platform" and "come and program on everybody's web platform".