Why Rinse?

A while back, when I grabbed a glass off the drying rack, I noticing something rather intriguing: there were bubbles and dirty dishwater residue in it. I simply thought it was an isolated and accidental case - everybody misses a spot here and there - and reached for a different glass. Then I grabbed a spoon and again, that nauseating little spot of dishwater residue was in the bottom of the spoon. I concluded that either the lighting in the kitchen was bad or the person who washed these particular dishes was acutely blind. Again, I grabbed a different spoon and no second thought was given to the matter.

The unrinsed dishes kept turning up, however. What is going on here? This was definitely not any type of isolated incident. Glass after glass, plate after plate, spoon after spoon all had sick, soapy residue on them. It really started to weird me out. Finally, after observing one of my roommates wash his dishes, I was able to diagnose to situation. Sure enough, no rinsing was involved - the dishes went straight from the dirty dishwater-filled sink to the rack.

"You don't rinse them off?," I inquired. He didn't know what "rinse" meant. Fair enough. I explained the meaning. With incredulity he answered, "Do you want me to rinse them off?" I didn't want to create a stir so I replied in the negative. But, being a sharp guy, he perceived my qualm and courteously proceeded to BLOW a few of the bubbles off the pots he had just put on the drying rack. Oh, ok, thanks man.

I really don't get it. Neither one of my roommates rinse their dishes. And it's not like they are unclean slobs; on the contrary, they epitomize German neatness and cleanliness. It just makes me wonder if they rinse off in the shower.