The collectors, the art dealers and the egg-head liberal art schools/departments are ones proclaiming that Picasso's later modern works have artistic merit. They are trying to uphold the value of their collections, livelihoods and reputations as art "experts" in order to keep the gravy train alive. After all, there is still a lot more Picasso modern art junk pieces to sell.
Did you ever see the documentary film F FOR FAKE narrated by Orson Wells? Well worth watching, but watch out! A part of that documentary is also a FAKE, just to show how easy it is.
http://www.imdb.com/title/tt0072962/?ref_=nv_sr_1