I think you know how the expected points work, so I'm not really doing this to "argue with you". Agree that our FG kicking is abysmal, but I would still put the expected points at that kick very close to 3. If NU scores, kickoffs to Wisconsin, then NU is able to stop Wisconsin, based on average field position created, I would think that NU would probably start the next possession between their own 20-30. Having to drive that length of the field against Wisconsin's strong D would probably have an expected point value of 1-2. So the expected value of this situation is 3.5-5 points.
But, if NU is able to convert that first 4th down ~50% of the time, the expected points from that drive would be 3.5. Also, given that Wisconsin is starting deep in it's own territory, I would argue that NU had a very good chance at starting the next possession inside it's own territory with probably another ~50% chance of scoring a TD following a short field. So, the expected points from the 2nd possession would be 3.5 points again. So, going for it on 4th down creates an overall expected value of ~7 points.
So, looking at the expected value of the 1st situation, it's probably 3.5-5 points. The expected value of the 2nd situation is ~7 points. I would rather have 7 points vs. the at most 5 points. Finally, when facing a strong defense, and getting within 5 yards of the goal line, it's smarter to try to get the 7 points! Settling for 3 points is what Wisconsin wants you to do!