We should worry about them, I agree, but lets put it in perspective is what I suggest. Because meanwhile there are MANY other "obscure" primate species including the ones that the team I'm part of are trying very hard to conserve that are slipping towards extinction.
Orangutang, gorilla and chimpanzee (and at least up to some point three of the lion tamarins) conservation is by comparison funded to the hilt and I do think this has to be both challenged and addressed.
We cannot have species like the buffy headed marmoset, James' sportive lemur, Rondo dwarf galago or the Roloway monkey vanish from the wild when these primates could be to some extent conserved for a mere fraction of the costs of what is pumped annually into great ape conservation.