This reminds me of a situation that played out with Mack Brown and the Texas Longhorns in 2010. I was a junior at UT at the time. All year long the Longhorns were blowing out teams and inserting the backup (Garrett Gilbert) at the ends of games. The thing is Mack Brown was always overly concerned about the perception of running up the score on opponents and making sure to win in a classy fashion, so he never allowed Gilbert throw the ball and run the normal offense to, ya know, gain experience in case he's needed down the line. Well the national championship comes around and lo and behold, Colt Mccoy gets knocked out of the game in the 1st quarter by Bama DT Marcell Dareus. Insert GG. The 5 star held his own but not after taking awhile to knock off the rust. There is a lot of regret till this day in Longhorn nation about how Mack handled Gilbert during the season because that Bama game was still winnable if the kid hadn't entered the game so "green".
Romo needs to play in case we need him due to a Dak injury or Dak "deer in the headlights" moment. It's not fair to Romo to expect him to come in under those scenarios and win us a game without any playing experience in 4+ months.