1. AAA isn't always there at your beck and call. 2. The mechanics of changing a flat don't exactly take years of training. 3. Some degree of self-reliance is generally desirable although that degree may be a reasonable topic for debate.
Sure if you don't want to do it, there's nothing wrong with that. But many smart people don't learn simple practical things for the same reason many practical people don't learn intellectual things, they put them in the too hard or too boring basket. You tend to be good at the things you work at, and work at the things you like.
In modern society, is knowing how to change a tire more practical than understanding the basis of argument?
> You tend to be good at the things you work at, and work at the things you like.
You work at those things which bring you utility. It's a subtle difference, but utility includes activities you don't like but which generate income. Ideally, those activities are also beneficial for society. Critical thinking is more highly valued in modern society than is knowing how to change a flat.
In fact, a scholarly person refusing to learn how to change a flat tire is of benefit to society because it frees their mind to contemplate more complicated matters and allows for less the less ambitious or less capable to still have functions in the economy.