The lack of sustained drives was a function of two things:
1. Key penalties negating plays and/or putting the team way behind the sticks in each of the first two drives... both of those drives had 10 yard penalties); the end result in the first drive was an 18 yard completion wasn't enough to earn the first down; the second drive holding call pushed UConn back to midfield and led to a pair of passes which gained a total of 5 yards.
2. UConn's inability to pass in the second half... there was a combination of factors at play here. Syracuse adjusted and did a much better job of getting pressure on Fagnano in the second half, this kept him on the move and his accuracy suffered. Add to that a couple of plays that could've been made and were not and suddenly Fagnano was in the midst of an 0-5 start passing going into the final "turtle" drive.
In fact, the only UConn yardage gained in the 4th quarter until the final drive was on the ground (they gained 57 yards rushing in the 4th quarter before the "turtle" three & out... Fagnano did not complete a pass in the 4th quarter until Skyler Bell's one-handed grab in traffic on 4th down.
UConn's inability to keep drives alive was why I told my wife, "this doesn't feel comfortable" up 17-6. They teased me by getting it to 4th down before the blown coverage on Ross-Simmons led to the first score and a massive momentum shift. Even then UConn began the "turtle" drive with 2 carries for 31 yards, plus a Syracuse offsides for two first downs... Then -4 (ok); -3 (really wanted to see a screen pass); no gain (this was fine (IMO), 3rd & 17 at this point you're committed to burning the clock, trying to pin them back (unfortunately the punt got to the end zone) and you tried it with a trick play to your best playmaker) and well we saw the result.
The defensive concerns:
The biggest factor to me was three 20+ yard pass plays on the final two regulation drives for Syracuse. That's not prevent defense, prevent defense is designed to prevent "chunk" plays and deep completions; that's three outright busted coverages. UConn spent the whole game with bend but don't break defense; they broke three times in the final two drives and it bit them.