Well, given the difficulty of all these questions, you can hardly blame nihilists for concluding that one obvious solution to the question of meaning is that it’s a wild goosechase. It’s plausible enough.
As far as pessimism goes, I would draw a distinction between pessimism which has been won honestly and deserves some respect (though not necessarily assent) and glib pessimism which deserves contempt. And that will always be a judgement call. The danger of pessimism, of course, is that it might be disabling in situations which aren’t futile; the danger of optimism is that terrible sacrifices might be made in situations which are. Upshot: don’t have a rule of thumb about what’s possible. But Kahneman says we under-estimate the accuracy of pessimism and I think that’s filtering out into an uptick in pessimistic predictions.
Other than that, though, I agree with Royce. I think nihilism is an essential part of many debates and I’m not sure I’d trust one which ignored it entirely. But it’s not a helpful view in itself and people who say “nihilism, end of story” aren’t particularly bright. The only real question around nihilism is “if nihilism, then what exactly?” which, as you and Sciborg have both pointed out, nihilists aren’t good at answering. You could say they have a theory with no model. I don’t begrudge the theory and I think it provokes useful discussion, but without a model, so what? Same goes for eliminative materialism. When it offers a model, I might care more, but until then, it has no force to it.