Some humble suggestions for how one ought to live their life.
Some worries with this rule. (I.) There is some controversy on whether "ought" statements should be admitted into logic, since statements which use the words "ought", "should", etc. are neither true or false. This is because such kinds of statements are not empirical (like, "The cat is/is not on the mat") and they are not just true by definition either (like, "A triangle has three sides.) So when you state "School curriculum ought to be based on a subject's usefulness in daily life," maybe you're not saying anything! (II.) If, contra to the worry above, you are indeed saying something, it might be false. The trivial worry is that everything can be made useful in some way or another, given the right context, even if the odds of that context appearing are astronomically low. So, on that logic, anything is fair game for school curriculum.
Well, this rule and the next one are a small side argument not necessary to prove the conclusion, so it's not fatal to the argument if they're inconclusive.