It's almost ghoulish, many people would say, although I'm sure that keeping an urn with the ashes close by is a source of comfort for other folks.
What I really can't appreciate is the idea of spreading the ashes over the sea or across a golf course or something like that, which is done because "that's what he (the deceased) liked." To me, doing this sort of thing has no meaning except that what remains of the physical, tangible, part of the loved one is forever obliterated.
As for passing an urn with ashes down to later generations to hold and revere...no, those people will most likely either scatter the contents somewhere or other, which is most likely against the law, or else they'll pay for a plot in some cemetery which has set aside a section for that purpose.