"Sincerity" here is a stand-in for "the correct side of history." What the article poses as a problem is part of what makes DE actually good - the game suggests that "correct side" to be fantasy: there is only struggle, and "a better world" is contingent. https://www.vice.com/en_us/article/7kpjzq/disco-elysium-was-too-afraid-of-sincerity-to-be-revolutionary

Harry continually resists traditional player - player character projections, which means players continually have to question themselves. But the inertia of just projecting onto the PC seems to be stronger than ever here.

That's why I prefer to understand its politics in a Gothic key: hope and melancholy become indistinguishable from each other. Elysium's corpse is but a taste of the corpse we are soon to live in.

"Revoultionary sincerity" wants to erase complexity and history, wants us to have no secrets, to have no wild desires, to achieve no joy unless we are sources of transparency, of self-erasure.

Anyway, perhaps I have too many thoughts on this game. If anyone's interested, I wrote about it here: https://www.fanbyte.com/features/history-life-and-death-in-disco-elysium/

And thanks @shredfearn for pointing me towards the article. I did enjoy it, though I disagree completely! :)