@boomerang,
I understand what you mean.
I think, it might have to do with .... well, most Americans have immigrants as ancestors.
But when their children (or they) look back at the country they are coming from, they behave similar to emigrants in my opinion.
And then it's not heritage but tradition, in my opinion.
We've a procession in my native town since 1622, because the twon was saved from
Christian the Younger of Brunswick.
So, the citizens and the town's councillors made the vow to make every this procession.
Most look at it as a tradition. And those, who call it an heritage mainly mean by this that it is a burden to go 'religiously organised' around the town wall