I think it's a good question and shouldn't have a negative score. Reading order is definitely on-topic, and this particular case is one where the answer isn't obvious: New Spring comes first in in-universe chronology (a prequel), but it's in the middle in terms of out-of-universe chronology, and involves concepts and characters not introduced in the main series until several books in. A good answer would require knowing which concepts and characters are introduced when throughout the series.
That said ... it's been deleted by the Community bot four times now, and undeleted each time by Mithrandir (sometimes helped by me and/or Gallifreyan). It's starting to seem a bit ridiculous.
I suspect part of the reason for the downvotes may have been the meta effect. This discussion about the now-deleted answer to that question became very heated, with a large group of users from another site piling in to vote and comment as well as attention from moderators across the network. Both of those groups of users may include people who dislike all reading-order questions, and who found this particular question through meta which they otherwise wouldn't have seen. There are a remarkably high number of votes (7 up, 9 down) on the question; 16 people voting is unusual for any non-HNQ on this site, and I suspect not all of those 16 are particularly active users here.
The point of all this is not to sling mud - everyone is entitled to their vote, active user or no - but to make the case that if it were re-asked today, the question would probably be received better. Normally I'm hot against people re-asking poorly received questions instead of simply editing to improve them, but if my hypothesis is correct that most of the downvoters aren't Lit regulars, then editing this question is unlikely to change its vote count by much. So in this particular case (without wanting to set any kind of precedent), I think it would be acceptable to leave the question deleted and re-ask an improved version of it.
How to improve it? Well, some explanation of why it's a decent question, why the answer isn't obvious, would make a good start. Something like the first paragraph of this very meta answer, for example. I'd say we should give @Riker himself the first chance to post an improved version, but it wouldn't be inappropriate for someone else to do so instead.