TLDR - Why make it harder for people to get help on the basis that some people might get help who don't deserve it?
means testing kills the usefulness of these kinds of stimuli. I completely disagree with your point here and the people buying Gucci/LV are a drop in the bucket compared to, say, Wal-Mart's yearly wage theft statistics.
There is no simple means of identifying who is in need and if people get the help who don't need it they can redistribute it if they are morally inclined or do hoarding or w/e; who cares?