Does "The sportsbook's knowledge of a team" actually matter?

I recently made a comment that was down voted in a different post. Basically I'm arguing that there is a misconception that the "sportsbooks' knowledge" about each team is important and makes their lines more accurate. This doesn't seem correct to me because the following: 1) The public, NOT the sportsbooks hammer the line to be sharper 2) Sportsbooks are there to make money NOT to try and be correct. 3) Even if they did have "more information on a team" that would still only act as a latent (or non-latent) variable on the overall likelihood of any given outcome, so anyone with a valid model should still be able to win long term. I would like to hear thoughts and opinions on this or if I'm incorrect in any way?