The point was to show what sounds you can get out of a very simple instrument, not to change your preferences in music.
I personally don't listen to Nirvana and probably never will because I don't like that style of music. Just because I don't like Nirvana/Cobain that doesn't make it lame suicidal junkie stuff, it just means that I prefer other kinds of music.
Lots of people love Nirvana...go for it.