Open Season on Commencement Speakers

I think a job that currently scaling the ranks of "Most Dreaded" has to be that of recruiting commencement speakers for college graduation ceremonies. Protesting them and shutting them down seems to be a sport today.

I don't agree with everything said in this New York Times piece, but I think the columnist raises some good points and questions about this issue. Is a commencement speaker meant to inspire and/or challenge graduating students to show excellence and grace in their futures? Or is his/her presence or un-invitation reduced to a political statement, regardless of how little their political views play into their purpose in speaking?