In an article in Inside Higher Ed by Jason Stanley there are a series of assertions to the effect that philosophy is somewhat alienated from the rest of the humanities. Part of the problem with assessing Stanley's argument is that it seems to be based exclusively on evidence from the US and to assume that "philosophy" is identical with contemporary Anglo-American writing. Stanley also appears upset that many people not employed in philosophy departments might be thought of by some as "philosophers" though why the particular employment designation should affect serious evaluation of whether someone is engaging in philosophy is less than clear.
Later Stanley claims that there is a general perception that the debates of philosophers are antiquated though, in including debates about the nature of justice amongst those thought to be "antiquated" he is surely asserting something that is dubious. Stanley later claims that philosophy was, in any event, particularly responsible for shaping the nature of modernity though, in making this claim, says nothing about how such a philosophy-shaped modernity might end up alienated from the philosophy that formed it, something that one might think required a very specific theory, perhaps on the lines of Adorno and Horkheimer's dialectic of enlightenment thesis.
Rather than investigate in what sense a philosophical account of modernity can be ventured, however, Stanley instead asserts as if it were obvious that there is no room in the contemporary humanities for such grand theorising as was practiced by Kant and Spinoza. The basis for the general claim seems to be that there is no audience for philosophy outside the university. This claim is a very difficult one to evaluate and depends partly again on what is meant by "philosophy". Certainly, as Stanley indicates, fiction has more general influence than any specific element of the humanities on the culture as a whole. However, much fiction is shaped by philosophy in quite a number of ways, not just fiction avowedly philosophical either. Again, a number of philosophers are widely read outside the university, though not many contemporary Anglo-American ones are. And it is this that again seems to irk Stanley though when he argues that Saul Kripke is more part of the tradition of philosophy than Slavoj Zizek he is surely right. Hardly anyone, however, including Zizek himself, views Zizek as a philosopher!
The concluding comments in the piece argue that the basis of the alienation alleged to exist occurs due to the practice of philosophy in a way that bears little relation to historical questions. This is, again, a particular practice of philosophy. To seriously study Kant or Spinoza without attending to historical matters is pretty much impossible and to read even 20th century analytic philosophers without some historical sense is pretty odd. So, overall, it is possible that it is something to do with a certain construction of what philosophy is thought to consist in that leads to the conclusion that philosophy is alienated from the humanities.