I suppose today wasn't a good day for a coach to bring up this subject (because it may look like sour grapes), and I'm not sure exactly what situation or situations he was addressing, but I agree with that a recruit shouldn't commit just to hold a scholarship and then keep looking.
I also believe that there ought to be something to a commitment/verbal. It shouldn't be meaningless. That doesn't mean that a committed recruit shouldn't or can't change his mind later. I posted several days ago that there should be some amount of ethics in recruiting and honoring commitments by schools. The situation involving a new head coach is a bit different, as the new coach hasn't made any commitments/offers before he became the head coach. However, even in that situation, pulling a scholarship is something that can cause issues (and I'm fine with high school coaches and others complaining when that happens).
Maybe some of you run around making verbal commitments, in life or in business, with someone you are dealing with, and then back out, but I don't if there has in fact been a commitment and there has been enough contact and communication so that both parties know that a commitment was in fact made. And if circumstances change, I get right back to people to address and discuss the situation directly.