Hi, I'm sorry to add my two cents into this discussion about the mood of users' posts, but I've seen it pop up several times over the years and I feel like there has to be a compromise out there that is more inclusive. I respect others may not agree, but I personally feel the thread should be open to healthy and respectful discussion, which includes pessimistic thoughts as long as they are obviously genuine (though it may be hard to tell sometimes).
Trolls/haters will continue to exist regardless of the tone of thoughts here, whether either by taking advantage of negative ones or calling optimistic ones delusional; so it's better to welcome those that need the fandom support from the thread rather than push them away for the sake of those looking to abuse it. The latter can be ignored, or if in the thread, banned/deleted with the help of mods. Quiet/unsure shippers can either be welcomed with open arms - making the fandom better, or be pushed away, which obviously is unwanted.
I've also had personal experience with being on both sides of the equation - being both optimistic about SA and pessimistic. While I personally preferred reporting most of my pessimistic thoughts privately, I was privileged in that I had fellow shippers I befriended on here and ProBoards. Some people don't have that advantage, especially others who lurk and may feel confused over both their optimistic and pessimistic shipper thoughts. They probably need chances to form that camaraderie, and that won't be possible if such discussion is pushed back against.
Potential improved inclusivity might be hard to enforce, but I think there could be a compromise between people actively seeking to discuss other topics and those looking for positive thoughts by the former or anyone really spoilering thoughts that may be more sensitive. It might not be doable as newbies might not know, or others may forget/be bad at HTML, but it could be a solution to what different kinds of people want to seek or express in the thread.