Locker was going to be the #1 pick in 2010...yes he looked bad his senior year, but he STILL was a top prospect.
One person thought he was going to be the #1 pick in 2010. He got a 2nd to 3rd round grade from the NFL advisory. He looked just as bad his senior year as he was his junior year.
I think it's difficult to isolate the prospect at the time from the additional information that has been accumulated. For example, I know I and many others had Locker as a fourth round prospect before that draft. Great measurables and a great kid, but his film was poor. This is a guy who was completing 55% of his passes and they weren't drops. There were just a ton of bad passes. Really other than the 4.5 speed I can't think of any area where Locker would have been rated above Tannehill, but now people are thinking "Locker was a high pick and he didn't look that bad in the pros". Ponder was generally considered a 2nd round pick at best and some had him as a third. You didn't hear late first early second like you hear as the lowest value rating on Tannehill. All of these guys had as many or more questions and doubters as Tannehill does now.
Saying that Newton was a sure fire pick is plain silly. A great deal of people thought that Gabbert and Locker were better picks than Newton. No way is Tannehill ranked lower than Ponder, Locker, or Gabbert coming into the draft. Ponder was thought to be a second round player, coming into it. Tannehill is widely viewed as a top 10 pick.