There really is nothing Adobe can do about how non-Adobe software functions. The PDF standard is no longer controlled by Adobe, it's controlled by ISO. Some PDF viewers choose to have no support for forms, some have pretty good support, and some (like Preview) are simply malevolent. There is a lot of non-Adobe software that creates bad PDFs, and a lot that doesn't have nearly the support of Acrobat/Reader. Again, this isn't a problem Adobe can solve.
Regarding, allowing image formats with the buttonImportIcon method and Reader, I know a feature request has been submitted for this. Reader 11 is the first version since Reader 5 that supports this, so I have hope for the future. In the mean time, it's fairly easy nowadays to convert an image to PDF. Even Preview can do it.