I think we need to manage expectations - but that said, I also think some are managing their expectations a little too much. 14 points per game is, to me, unrealistic (but that's not to say that that shouldn't be where Boyd is aiming). However those suggesting a horrendously low GPG average due to "taking time" are going a little far from my perspective.
Talls do take time, especially in the frame that Boyd is growing into. However historically the lack of goals kicked by future champions early on in their career is overblown. While most are relatively average in many areas of their game in the early stages of their career, the amount of goals kicked in a young key forward's (who goes on to be a very good player) second and third years are mostly decent. I picked ten past and present top-line key forwards at random and looked up their second-year stats:
Travis Cloke - 6 goals from 15 games
Jason Dunstall - 77 goals from 22 games
Tom Hawkins - 13 goals from 10 games
Jonathan Brown - 38 goals from 25 games
Matthew Pavlich - 28 goals from 21 games
Jack Riewoldt - 18 goals from 8 games
Gary Ablett, Sr - 33 goals from 15 games
Wayne Carey - 38 goals from 21 games
Lance Franklin - 31 goals from 14 games
Nick Riewoldt - 21 goals from 22 games
On average, these players kicked just over 1.75 goals per game. If you take Dunstall's stats out of it because of how ridiculous they are, they still averaged a little under 1.50 goals per game. Looking only at present players to correct for changes in game plan, etc, they kicked just under 1.35 goals per game.
My point in all this is that we need to have a look at what we want Boyd to become and compare him to those that reached that sort of level. We guaranteed him millions of dollars as a teenager and gave up our captain (a genuinely elite player) and a top-class pick for him - we both want and need him to become, at worst, a very good key forward in future. This isn't going to happen overnight and I don't believe we can go into the season expecting anywhere near 50 goals (and before anybody comes at me with a, "We're not paying him millions of dollars to kick 20 goals," remark, we aren't paying him millions of dollars next year - he's earning draftee wages) as it just doesn't happen very often. The list above, in my opinion, covers a good range from 'very good key forward' to 'genuine superstar key forward' - and we want Boyd to be somewhere approximately within that range. As such, his numbers should be around the mark of these guys in their second year. How you interpret the cutoffs of a 'pass' or a 'fail' on the year from these numbers is, of course, subjective, but I think it's a relatively good way of looking at it.
Personally I would be looking at something above 1.2 GPG as being a pass. It's a respectable increase on his first-year average, as well as being close to many of the players mentioned above.
So 1.2-1.35 is a pass, 1.5 good, 1.75+ very good? Sounds fair to me. (And thanks for a "brief" post that I can digest in a few seconds at work! )
(But, what if he plays, say, 18 games, kicks 27 in one of them but doesn't kick one in the other 17? That's 1.5 GPG too!)