An opinion informed by hearsay, which isn’t without value in some contexts, but which is not going to be of value when joining a conversation being had between those who have actually experienced the work and are discussing it.
Not meaning to beat up on anyone here but I will use @DemonTree as an example, in the discussion about the show “Adolescence”. In a CS about the show being had by those who have seen it, comments arguing that the show is unfair to men and to incels made based on what they have heard about the show in forums, and not having seen it, were not welcome, and were simply ill informed.
The same sort of thing happened in the discussion of “Poor Things” when someone who had not seen the movie got on a high horse lecturing those who had over what the movie was, how awfully misogynistic it was, based on hearsay.
This is a different sort of thing than making an educated guess that the work is not worth your time or not for you.
Now no question works not personally experienced can be discussed in broader discussions, but when someone with direct experience contributes that the work is actually other than what you had heard about it then its value as an example to be used by you is … lessened.