I see that it can be useful to copy keyframes only (as you described above in keygraph editor) and it can be essential NOT to copy them with the object.
But I have found it annoying so many times, that I have to do those two steps when I WANTED to copy object+keyframes. Just think, that you want to copy 20 objects - with the described 2 steps it IS annoying.
Me, simple-minded, I would think: why not integrating a "copy with keyframes" menu item? You just could select 20 objects in the object inspector and "copy with keyframes" them and paste them afterwards within 10 seconds.
Regards
Sefa
#XPression