I studied both a science based degree, and a history/archaeology degree and let me tell you, writing to make an argument and reading text critically? I mostly credit the arts bit of my education with those skills; also, history is just fun.
There are lots of ways to answer this and one of them is that studying history makes you a better citizen and our public universities have an obligation to produce good citizens. History education is essential to a republican model of government. Engineering is not.