The problem with Wilson is the lack of volume. He has only thrown 30 or more passes 3 times this season. Even with the proverbial handcuffs taken off, he simply does not throw the ball enough to reach QB1 (top 12) status in any given week.
Maybe that changes next season, but for now the Seahawks would much prefer to keep Wilson in the 20-30 range for pass attempts and continue using Marshawn Lynch as the primary engine of the offense.
That's the biggest difference between Wilson and the "big three" of RG3, Luck, and Tannehill. The offense runs through those three guys which is what you want in you fantasy QB