When considered with other factors: a powerful tool. Agree though I wouldn't just fade the public blindly unless they have been getting creamed.
Many of these lines are situation and perception. Case in point: Steelers -10.5 vs Shitty Indy and close win by 3 points. Next week they are -7 against a 'better' Titans team (win streak, mariota, etc.) and the public thinks "ah, +7, easy" ... Really there's nothing better than fading a public dog.
The game tonight is a pick -- put your money on the better team and hope for the best. If you lose, at least it was your pick and not a blind fade. Maybe try to buy out of the wager with an in-game bet if you can. I did that last week with NIU.
I personally think Russ Wilson is slow and holds onto the ball like an unfinished cheeseburger he refuses to throw away. That said, Seattle is at home and shit happens all the time in this game -- Like who the hell had the Giants beating KC??
I look at it differently. Pitt -10 was a good line, nobody "wants" Indy against a top notch team like Pittsburg, do they? Pitt came out lethargic, not excited on the road against a bad team, Steelers have been around the block and already confident that they will get into the playoffs with a strong record, no reason to be jacked up. Indy is bad but is a pro team at home, fought hard, covered the spread.
The Titan line was fine, +7 was fair, not deceptive. Mariota is overrated and when they could not run he is not a pocket passer that can make up a deficit. Steelers were up 1) for a national TV game at home and 2) cause Titans were rated as a playoff caliber team.
You are a good capper but I think both lines were right, I do not think either was a trap or Vegas conspiracy for the public (more than any other game).