I don't think that's why kids hate it. Rather, teachers fail to explain the underlying motivations, the reasoning and the purpose which makes math feel like arbitrary decisions.

I'd argue math is much more uncertain than other subjects. What's the purpose of the endoplasmic reticulum in your cells? Just memorize the textbook. Find all X such that [statement] is true? You better have some creativity! Or a lot, depending on the problem.

Some accompanying evidence for uncertainty: https://xkcd.com/2117/