Even if it is a guess 100 out of 100 times if you have 4 options a blind squirrel is going to guess correctly 1 in 4 times. So if you do this 4 times you will win 100 points. If you instead take the 20 points 4 times you will win 80 points. I reckon that 100 points is better than 80 points.
I think SBR made the point structure the way they did to profile mathematically challenged players for the books. What a strategy.