If we can't disprove the Gettier stuff, perhaps we can hope that people will get bored of it (if we provide them with a less boring alternative).

When you can't disprove something the straightforward way is to accept it. In this case you can switch to a more construtivist notion of knowledge. To quote Heinz von Förster: "Truth is the invention of a liar."

Perhaps we should instead focus on showing what alternative things philosophers could do. Also we should make alliances with other subjects. People outside the discipline are much more likely to want to fund work on business ethics or medical ethics than yet another go at some concept or metaphysical question.

The problem isn't that you can't do anything useful with ontology but that a lot of analytic philosophers are confused about the subject and produce papers that provide no value.

Barry Smith does deal with the question of knowledge and get's funded because he actually does something useful. Applied ontology is useful for bioinformatics and other fields likely also would profit from it.

It possible that in one or two decades bioinformatic inspired mapping of mental states is good enough that the psychology folks with their DSM simply loses it's authority.