I think you, and anyone else who shares that sentiment, are looking at it from a shorter scope. Using their heads is going to have them in contention within the next two years as opposed to another likely rebuild after a historically bad effort in Year 1 in which we have to overpay free agents in Year 2 to play for a rookie QB. Besides the Colts, who already had an established coach and front office after Manning left, you won't find any team recently who has followed a similar method and won.
Say we rolled with Rosen, who's to say
A. He doesn't progress throughout the season and we win 3-4 games?
B. Flores is still employed after a 1-15 or 2-14 season?
We'd have to go into another offseason playing catchup because we're searching for a new coach(es), and possibly a new GM, to install a new offense & defense while also banking the future of the team on a rookie QB.
Even if Flores were to stay after a horrible season, history proves that coaches who win between 0-3 games in their first year rarely if ever work out.
The "I'm used to this already" crowd are hilarious considering we havent been in a situation like this.