I love this thread and I love the question, but I really loved the Aucoin and Locke comparisons.
To the Original Poster, I definitely understand your confusion, but this is something that you learn as you review prospects. I only worry about prospects from a Fantasy Hockey prospective, but even still Jordan Weal routinely looked relatively strong in comparison to many 1st rounders in his draft class based on stats alone.
I think what has failed to be said directly is that it's not as though showing the ability to score at the rate that Weal had scored at wasn't valuable. it certainly was an asset to his cause and was the main reason that he was drafted as a 3rd rounder. However, as we know from all sports, being able to excel at one level, and projecting that talent to the next level are two different things. I love the individual insight from some of the other posters as to the many reasons that people are worried about his conversion to the NHL game.
But really, the reasons why aren't relevant in this situation. There are two overlying factors that GMs look at when they are evaluating talent for an entry draft: the first is the player's absolute highest end impact. and the other is the odds of the player reaching that high end impact. This is true for any sport, not just hockey. In this case, Weal has two things working against him. He doesn't project well, meaning it's very possible that his talent looks as high at 17 as it's ever going to look in his entire career (and there are hundreds of cases of this throughout NHL history). The other issue is that while not impossible, it is much less likely that Weal does what his major junior numbers say he can do than other talented players.
Is it possible that Weal ends up being a steal for LAK? Absolutely. I look forward to seeing what he does at the higher levels. My guess is that as much as I like Weal, he will end up like a Locke or an Aucoin (or a Jeff Clement or Brandon Wood or Brad Eldred if you know baseball), as an extremely good minor league player that is just that, an extremely good minor league player (called AAAA players in baseball).
Considering what he's shown he can do at the WHL level, his signing shouldn't be a surprise to anyone, but just because they're willing to take a flyer on him, does not mean that they plan on having him on the team in 3 years. It simply means that if he does pan out, they want to be the ones getting the rewards.