Yes, Libratus sounds incredible, however, does it exist as an independent and playable entity?
To build the program (Wikipedia) it took 15 million core hours of computing and during the one tournament it played it used another 4 million hours of computing to analyze the in-tournament play. I presume this is all via super-computer so the program is not set up to play anyone, anytime.
However, I agree it seems a shame Libratus has not been put to more use/challenges. That said, has it simply been accepted with this much AI/computer power it could run circles around any human regarding NLHE? So it would likely be a waste of time and resources even if they sat the likes of Stephen Chidwick, Justin Bonomo and Steffen Sondheimer down to face it as they would also be chewed up and spat out within a few days?
I am sure there are countless research scientists who would love the opportunity to have several days of that much computing power at their disposal and it might simply come down to the idea they do not need to repeatedly show they can beat humans at Hold'em.