It is quite clear that you don't understand the problem !.
GPS is no doubt far better than an NDB but it has its problems the biggest is that it is not hard to jam GPS over a wide area and if that is done what is the back up system for IFR traffic ?.
VOR and ILS systems are expensive to maintain so the good old NDB is the cheap alternative, I know this is far from ideal but I think that it will be this way for some time.