Yeah, this is just the latest in a string of surprising (IMO) moves by Lovie:
1) Drafted nearly all defense & ST in the 2006 Draft
2) Stuck with Grossman all season
However, the last few resulted in a Super Bowl berth, so I'm thinking there's a method to the madness. He certainly doesn't let public opinion decide things for him!
I've also heard this is at least partially a $$ decision by the front office. With all the HC interviewing Rivera's been doing, he obviously will expect a raise to keep him in town. Lovie's known as a defensive guru, so why pay big money for a DC?