One might just as well argue that burden is on metaphysicists, to show that what they're saying is useful.

That's precisely the proper response to any proposed wonderful activity: show me the payoff.

And don't tell me all the truths you can produce - show the payoff of those truths. Show me what you can do with them, that I might want to have done.

Academia is full of people producing stacks of bits. That activity is very profitable for them, but I fail to see the payoff in many of those bits to anyone else, and in particular, me.