Well Brian...since you asked:
Growing up in the Bronx...just a stones throw from Yankee Stadium created some interesting loyalities. On the one hand, when the Giants left the Polo Grounds, a lot of the older folks I grew up with were mad as h e (double hockey sticks). The children (that would be me) couldn't figure out what the fuss was about...Yankee Stadium was right there.
It was cheaper to take the kids to Yankee Stadium for a game...bleacher seats back then were $.50. The Yankee's fielded some interesting teams during the late 60's and early 70's...but they didn't win.
Fast forward to the mid 70's and all of a sudden, the Yanks start winning! My generation had never seen a winning Yankee team...we were all agog. The 1976 and 77 years were indeed special. This passion lasts because of the tradition of losing endured during the previous decades. I cannot speak for anyone under the age of 40, these folks have no conception.
So, from a life long Yankee fan...who lives in the Bronx, I hope you can understand the passion...so what we won for several years, resulting in Parades three years in a row? 8O For the record, I at least knew it wouldn't last forever. I'm comfortable with this.
(PS - I follow the Met's as well...since they are "The poor man's National League Team"...a phrase my elder's used when speaking of the defection of the Dodger's and Giants).