I agree with your idea, but I don't see at as a counterpoint. I don't read this post as making an axiological statement about the would-be reader's work (I may have read it wrong though!). To me, the article assumes that "finishing" the thing is something the reader already values, or at least does in many cases. And the author is offering some advice for how to stick to it and power through even when there are painful stages along the route to what the reader already wants. I see this as trivially or obviously true too, namely the idea that not every moment or every ounce of work on the way to something you yourself really deeply desire will feel like elation and fun.