New people are being born all the time who haven't had the opportunity to watch the entire history of television (or even just the best 10%). By spoiling a show that you've watched, you're denying them the opportunity to experience the joy that you had.
The logical conclusion of this attitude: "Therefore, all conversation of any form, especially any crossing generational boundaries, must cease immediately."
There is some information that people want to learn through conversation, some that people don't mind learning through conversation, and some that people actively want to avoid learning through conversation.
I don't know why you'd reach the conclusion that all information falls into the latter category.
> If you didn’t watch it yet, were you ever really going to?
Yes. I have the whole thing saved and did in fact plan on watching it eventually.
If you didn’t watch it yet, were you ever really going to?
Imo, spoilers without warnings are fair after 3 months time+ for TV shows and movies. Maybe even sooner.