why doesn't someone invent a clear toaster so you can see

there was a prototype of a really cool glass type one, where they ran currents through the class, it was so super cool. anyways, they couldn't sell it because over time, the glass would melt

btw it's not the same one as Seratonin posted

It already exists
http://www.telegraph.co.uk/news/newstopics/howaboutthat/6931661/Transparent-toaster-sees-end-of-burnt-toast.html