"Let's put this another way: "If I want what I have to say to be recognized by the academic elite as having value then I have to say something that appeals to the intellectual predispositions of the academic elite." Okay... is that the defense speaking, or the prosecution?"

It's reality speaking.  And "predispositions" here is simply a pejorative way of referring to the accepted principles and practices of any domain of expertise.  You recognize the domain of expertise.  You want very much to be viewed as a part of it.  That much is clear.

"Apparently your view is that if I want to challenge academic shibboleths I should scurry off to Amazon and self-publish my work; or to put it differently, I should come to the realization that the philosophical establishment is no place I would want my views aired, since I am so given to challenging what they deeply accept. But first, it seems to me obvious that when one wants to challenge an idea it is precisely the community that holds the idea to whom one wishes to address oneself. Standing completely outside it and shouting from a hilltop to a coterie of equally disillusioned listeners does not sound like a way to achieve that."

The litany of complaints we have seen in this thread are not from those who see themselves as conducting a crusade to "challenge the establishment", but rather those who are complaining that their (at least mostly) mainstream work is not getting published.

If you want to stand inside and shout, rather than stand outside and shout, then the time-worn techniques for doing this are well known.  You first establish a reputation as a competent member of the community who understands the accepted criteria and norms (which means you put in time and "pay your dues" by doing what is regarded as quality work and publishing in recognized and respected venues), and then on the basis of that you "challenge academic shibboleths".  Either you are willing (and able) to do this or you are not.  You are standing outside and shouting, and complaining that no one will let you in.  Silly.  Childish.  Fruitless.  And a denial of the situation.  But often a good excuse for not succeeding.