The Titans used the second pick in the draft to take a QB who hasn't taken a snap under center since junior high school.
Figures.
The Titans problems go a lot deeper than the QB spot. Does matter if they have Marcus Marriota, Peyton Manning, or Johnny Unitas back there right now. Until they shore up the rest of the team they are still going to suck. They could have used that spot to fill 3 or 4 other needs and still be able to acquire a decent QB later in the draft or with a trade.
I dunno. The NFL, much moreso than college, is a QB league these days. And if you think you have a chance to get a great one, you have to take him. A great QB can cover up a lot of other roster deficiencies (see Andrew Luck). So if the Titans think Mariota is in that class, then they absolutely made the right move. But I don't think he is. Time will tell.