Card Tricks In The Dark?
That's a good critique which nails down a particular shortcoming -- bathos. Using that you're saying that the story doesn't pay off (which is a fair subjective comment for any reader to make) because any point it reaches is banal in comparison to the complexity and convolution of what sets it up. And if you're saying the point reached is a private joke or a trivial factoid, that nails down the banality pretty precisely.
You could call that type of bathos "self-indulgence" but if you did, the problem is that you could equally well be talking about something else entirely. You could be talking about "therapeutic" writing which is not really designed for a reader other than the writer, but where the problem is inscrutability rather than banality. Scrolling down that Turkey City Lexicon, you could be talking about clumsy overuse of eyeball kicks, infodump that makes Tolkien look concise, "I've suffered for my Art" overload of research data, Kudzu plot and so on. You could even be talking about "them fancy polly-silly-abic words used by that damn smarty-pants writer; why, it's like he just gone and swallowed a dickshunary! Cuz, heck, Dan Brown can write a real good book with none of those there polly-silly-abic words that makes my head hurt! Why shouln't everybody?"
Point is, "self-indulgence" can mean anything from "one-person pay off" to "too many notes".
I remember getting a similar feeling of generalized bafflement from a discussion of "intertextuality" a month ago.
These terms seem to be shorthand for very extreme levels of contempt, with the conflict originating in the attempt to disentangle the dictionary definitions from the negative connotations of the shorthand versions. For all that the shorthand does still contain some of the original sense, it's probably useful to pull apart those two meanings before continuing.
I dunno, you could probably also go on to distinguish between "fundamental" and truly "digressive" self-indulgence, where "fundamental" self-indulgence is integral to the work itself, and "digressive" self-indulgence genuinely serves no purpose. But that would be an unfortunate naming scheme, since "fundamental" self-indulgence might be structurally digressive.
But, um, I digress.