When a Korean is speaking to me, he or she will often shift to a certain form of polite speech. Words shifted to a polite register sound different from the basic forms of the words I know, so in the heat of the moment it causes confusion. Each split second of slight confusion can easily add up to losing track of the point. They're trying to make me feel good (being polite), but it actually makes me feel...bad. I wish they'd stop being so polite!
This reminds me of something in New York City. In visits there I saw lots of signs that said things like this: "Accumulation of Refuse on the Premises is Prohibited". Why not just say "No Trash"!? In this case, this over-formal language is just not a good idea because many people will frankly not understand it.