Yeah classic conundrum.
9/10 times the QB needs to go down at the 1 - you have 3 shots at running it in and at worse you ask your kicker to kick a chip shot from what 24-26 yards max? I mean you have to take those odds.
Other school of thought as someone mentioned is relying on a college kicker (even a pro these days) to kick even a chip-shot is unfortunately very dicey and so you never give up guaranteed points. Take what's on offer and trust your defense.
I personally don't have an issue taking the points because going 70-80 yards with no timeouts and 1.51 left is pretty tough and the odds are really against you. Of course then up step "genius" defensive coordinators/head coaches who then play prevent defense, bring no pressure and allow even average QB's (pro and college) and their receivers any and everything over the middle of the field between 10 and 20 yards. Surprisingly easy to drive 80 yards and throw a score when you are basically playing practice scrimmage reps.
So with that being said, just take the friggin knee and let your kicker do what he's there for.