A knowledge of chemistry is important in the situation foremost because without it these reactions could be highly dangerous. Chemistry is also important with these chemicals because with a knowledge of chemistry these reactions could be put into great applications. Although after hours of searching I have not been able to find a direct application for alkali metal's highly explosive nature, the products of their reactions have numerous applications. For example, Lithium hydroxide is used as an air purifier, a lubricant, a catalyst and much more. Potassium hydroxide is used for a much wider variety of things than lithium hydroxide however not as many things as sodium hydroxide which is used in analytical chemistry, soap making, paper production, biodiesel fuels, cleaners, drugs, and that is just the beginning. These things could not have been made or discovered without a knowledge of chemistry. So I think the second reason chem is important here is for exploration and discovery...and we all know how chemists love that.
Mini Bibliography
"Group one: The Alkali Metals." Chemsoc. 28 Jan 2008 <http://www.chemsoc.org/viselements/pages/data/intro_groupi_data.html>.
"Lithium." 2008. Wikipedia, The Free Encyclopedia. 28 Jan 2008 <http://en.wikipedia.org/w/index.php?title=Lithium&oldid=187460066>.