So it's a measure of tone... and importance given by them.
Was Obama's a lash of anger, a moment in time... Was Trump's a lasting appeal, a political tool / rallying cry?
I think Obama meant it, and was consistent at calling out his opponents from start to end. Trump just has more opponents, and his style is not to speak carefully. Is he appealing to those divisions to some end? Sure... the media talks Trump 24/7 with full saturation. If anything, his "obsession" mirrors their own with him. It appears, to me, to be a simple matter of back and forth.
A thin skinned President who can't help but speak... poorly.