I don't know. Maybe I'm just old fashioned. But whatever happened to courtsey and respect? The golden rule? It is all the "This is my kid and he/she deserves applause" Well every single kid up there deserves it too. Why can't you wait until ceremony is over? Which brings up another point.
a letter to the editor (in my local paper) was someone saying that many people left the ceremony as soon as their kid got his diploma. Blocking people's view/camera angles in order to exit.
This falls under the whole "cell phone in the movie theatre" lack of respect for others that just sucks about our society now.
It is really too bad the school's choice was to punish the graduate. What should have been a memorable day was marred by this. If you ask the audience to hold their applause why can't people respect that?