That's fair.
But it gets back to my point - how many other successful college QBs - who were not projected to succeed as a pro - retained the popularity Tebow did before he had some successes this season? None.
Well, first of all, no other college QB in the history of the sport achieved as much success as Tebow did. None. So any comparison along these lines is going to be a little bit flawed. Note: I know you never said that other "equally successful" college QB...you just said "other successful" college QB. But my point still stands.
Tebow entered the NFL riding the biggest crest of national popularity I have ever seen, and for good reason. Not only did he possess the most impressive resume of all-time (and that's no overstatement), he was also viewed as pretty much an all-american kid. Good kid, good values, worked hard for the poor, did a bunch of charitable stuff, never got into trouble. I mean, think about that for a minute. Think about all the unbelievable crap that various NFL and college players do. Not only was Tebow not involved in any of that (lots of guys weren't involved with it); he took it to the next level and did charitable things that nobody else (that we know of) was doing. Obviously his faith was the driving force behind that, but if you forget that for a moment, you realize....holy cow, this kid has incredibly impressive character. So he was a VERY easy guy to root for.
When he entered the NFL, he immediately became an underdog, which is hard to say considering he was a 1st round pick. But he was because most people thought that he couldn't succeed in the NFL (and many people think he still ultimately won't). He retained his popularity probably because he didn't fail his first year. When he did finally get a chance to play late in the year, he led them to a remarkable comeback win against Oakland, and very nearly pulled another one off against San Diego. So the fans naturally wanted to see him get a legit shot.
And all he's done this year is win. Obviously we can think of a bunch of non-Tebow reasons for why Denver has done well (great defense, unbelievable kicker, some really good fortune, etc.), but nevertheless, he and the team are winning. So he remains pretty easy to root for, for much of the country.
It's not that hard to understand, really.