Youtube absolutely should care. The "long tail" is one of Youtube's competitive advantages. Sure, each individual video in the "long tail" may only have a couple thousand views, but collectively as a whole the "long tail" is the reason why you instinctively check YouTube over any other site when looking for:
"how to replace xx on 1998 honda",
"2002 winter olympics highlights",
"insert 1980s tv show name theme song"