I am going to weigh in with my own answer to this question. :-)
Many of the answers to the above examples fit within the "Guidelines for Great Subjective Questions".
1. Great subjective questions inspire answers that explain “why” and “how”.
Many of the answers to those questions provide key insights into the book or film series as a whole. Many provide crucial details about what to look for when watching. Or the answer describes important themes and philosophical concepts within the story.
2. Great subjective questions tend to have long, not short, answers.
Some of the answers to those "Should I" questions are long, complex, and thoughtful.
3. Great subjective questions have a constructive, fair, and impartial tone.
I'd say many of the questions and their answers are constructive and fair. (But that is just my opinion.) :-)
4. Great subjective questions invite sharing experiences over opinions.
I like answers to "should I read/watch" questions that describe why a person has a particular opinion. An answer that points out good character development, plot lines, or settings will often make me more interested in seeing a movie rather than less interested. Answers to "Should I" questions that mention bad plots or trivial character motivation are a great warning about what books not to read.
5. Great subjective questions insist that opinion be backed up with facts and references.
A lot of the answers provided to those questions are rooted in canon information about the movie/TV-series/books.
6. Great subjective questions are more than just mindless social fun.
I am actually okay with the answers being mindless social fun.
Edit to add:
Rand al'Thor wrote a really useful answer to this question. Please go read it and give him a thumbs-up. I like his explanations on why "reading-order" and "viewing-order" questions are good. Where we disagree is on "recommendation questions". I think recommendation questions can be useful.
If I were to answer a question of "Should I read Blindsight by Peter Watts?", I would answer like this.
! Some people like this novel, and some don't. It has good reviews and was nominated for a Hugo Award. It touches on themes of self-awareness, consciousness, and the evolutionary advantages and drawbacks of consciousness. It presents intriguing ideas about a crew with a vampire leader, a person containing multiple consciousnesses, and others with different levels/kinds of consciousness. It is a very intriguing story with a lot going for it. It's also one of the best First Contact stories out there, and to my knowledge, the only character-driven First Contact story.
! On the downside, Blindsight is not an easy read. Sometimes the plot is inscrutable and the characters are hard to relate to. As they say, readers must identify with at least one character in a story so they keep turning the page to see what happens to their character. It's hard to get into the mind of a character whose mindset is very different than a typical reader. For many readers, it is hard to identify with any of the major characters in this story.
! It touches on several complex and subtle themes. A good story can introduce those themes to the reader and make the reader think and rethink many times after they put the story down. It's hard to do that for complex topics, and a good author can pull it off. Mediocre authors barely touch on new themes and often just retread existing ideas and tropes. Blindsight fully engages with an idea that is often ignored in sci-fi; whether consciousness is an evolutionary dead-end. Kudos to Peter Watts for doing it, but it is hard to get at the themes in this book if you struggle to understand the plot and characters.
In all, Blingsight is as rare and austere a story as another great story about First Contact, 2001: A Space Odyssey by Stanley Kubrick. Each is hard to understand with a strange plot, unrelatable characters, and subtle themes that are hard to understand. Viewers walked out of the theaters in mid-movie asking "What was that about?" and many called it a snorefest. Several people I know have put Blindsight down after just a third or halfway through and said it was "too weird". Others praised it as groundbreaking. It's a rare story that can provoke both high praise and low contempt at the same time.
Whether Blindsight is right for you to read is question you have to ask yourself. I can describe what makes the story good (and hard) to read and leave it to the (hypothetical) asker to choose on their own.
A question asking for a recommendation of Blindsight may seem as too based on opinion, a good answer can provide insights into the story, and provide fact-based information about the story, so each reader can that answer the question for themselves.