Why doesn't he sell while he can still get something for it? Continuing the trajectory it has been on in the last two years will mean shuddering the paper or turning it into X hoping some users will switch.
You buy a newspaper because you're rich and you want your opinions disseminated. Not because you think you'll make money. So the number of potential buyers is really small.
Bezos is literally just showing his incompetence at this point in running a paper, and the NYT is probably loving it. Sure billionaires can buy social networks and papers, but people can also subscribe to and use things not owned by billionaires.
[1] https://www.natesilver.net/p/the-sad-and-self-inflicted-decl...