I think both the criticism and defense of Siemian is a bit over the top. The defense is a reaction to what's perceived as over the top crticism, and the criticism is driven by what's seen as over the top defense of Siemian (or in some cases belief Siemian is no more than a backup caliber QB).
I know that we can be hyper sensitive and critical of our QBs. It's the case now and has always been the case. The reality is whether it's Aaron Rodgers or Matt Ryan or Eli Manning, they all make good throws and bad throws. If they didn't all have bad throws, they wouldn't have picks and their WRs would make the highlight reels with amazing catches.
It's like expecting a batter to never hit a grounder to the third baseman or a lazy fly ball to center field. It's an unrealistic expectation.
Even QBs with 5-10 years experience make mistakes, young QBs make them far more often.
Also, we should not forget the Broncos offense isn't going up against blocking dummies, there is a defense on the other side of the field paid to stop the offense. When Carr made his mistakes, was that because he sucks or because the Broncos defense pressured him into making mistakes?