What is the purpose of a subwoofer?

i remember back in 89 walking through mccormick place back in chicago feeling this really really low b.couldnt hear it obviously but it was there...we walked and walked all around that place for about an hour and finally found the dude in the corner all by himself with not a single person around him asking him questions about his setup..it is the b that i have always aspired to obtain whether in a home enviroment or vehicle environment... it was all about the transients of that sub ...someday.. someday i will be able to... well anyways.. seems like most people whether on this forum or drivin around town put togethr systems so they can be heard outside of their cars..sort of odd i think.wouldnt a person choose perfect b in the vehicle for his enjoyment?. but back to the point... nowadays the contrab that was made by intersonics is obsolete... how does the perfect subwoofer not stick around ??? i have come to the conclusion that people dont know or care what good sound is.and while b is just one aspect of the music... it is the one that i enjoy the most. what do you think??