When fans have to line up excuse after excuse for why their young drafted QB isn't as successful as the next, it's usually because he's simply not as good as you think he is. The marks of a truly elite quarterback prospect is that your team is given margin for error, because your quarterback is that damn good.
You don't hear Colts fans making excuses for Andrew Luck, despite them having a myriad of issues with their team (poor offensive line, average to mediocre skill position guys, bad defense). It's because Luck, despite those issues, has proven with both his tangible and intangible abilites, that he can carry a team to the post-season.
If the circumstances have to be near perfect for Tannehill to succeed, then he simply isn't as good as you think he is. Eiter that, or you have low expectations for a 1st round, no. 8 pick overall.
Enough with the excuses. Put up or shut up for Tannehill in year three. I'm hopeful he can get over the hump, but I'm certainly not as blindly as optimistic as some here (you know who you are).