It's pure nostalgia again. It was on television almost every Christmas from 1969 to today. It was a Christmas tradition...
...and now unfortunately it's a tradition that is being copied by a thousand low-rent cartoons that even snatch the cover in their cheap imitations....
...but in any case, about two generations of American kids grew up with this as a part of their Christmas holiday, along with Rudolph and the puppet Santa cartoon. It's as much a part of Christmas as "It's a Wonderful Life" and "A Christmas Story," and it has spanned the generations.
Unfortunately it's on less and less now days and being replaced with, well, with NEW shows that don't have the generational love behind them.