the fact is in many cases, with gifts, or contacts, these things figure much larger in the lives of the older generation than the younger. on the whole.
the youngers' own lives are busier, for adults, or more interesting/fun, for children. the relative importance of things to do with oldies is quite different from the other end of the telescope. not that they would wish to offend or cause hurt.
but they just have other priorities. and they don't really grasp that time is passing.
and that when they have got the time to express their fondness, give attention to the oldies, it may be too late.