For all we know, the Broncos were embarrassed by the attention/controversy generated by Tebow's outspokeness.
Given the nature of the NFL and Tebow's performance last season I don't think its unreasonable to have suspicions.
It’s not an opinion, it’s stats. It’s not like they’re chucking him aside for Matt Hasslebeck, this is Peyton Manning. If the Broncos were embarrassed it was by his 30 total completions in the last 3 games of the regular season. Given the nature of the NFL and Tebow’s performance last season it’s completely ridiculous to have suspicions. 30 completed passes in 3 games. Who would keep that guy as their QB when a HOFer is available?