Researching and looking into what the game has to offer isn't "ruining" it.
It's going "I like the franchise, but what I'm seeing so far doesn't interest me. Maybe if I look at more of the material they are putting out there will be something that does catch my interest."
So you watch another video, read another interview. ANd you still aren't feeling it.
So you watch some more gameplay. And nothing is clicking for you. And after having been dissapointed with the previous outings, you really need to be convinced before you're willing to part with 70$ and 100 hours to try it.
So you watch even more trailers and interviews, hoping and desperate for something, anything to strike a cord to make it exciting and interesting and worth your while. The combat, the world, the characters, the premise, anything.
And it just never comes. And this continues for three years, and demos, and bits of information coming out piecemeal. You play the demo that they release. And not only do things come forward that don't excite you at all, but elements you actively dislike and don't want to spend time on at all.
And then close to release reviews come out confirming basically everything you've judged, but you do hear people saying "yeah the first half is lackluster, but the second half and the ending are amazing!"
SO you go "well, everything I've seen so far that I don't like is about the first half I guess. If the second half is really that good, then maybe it would be worth plodding through 20 hours to get to that amazing remaining 30 hours."
Then you look and there's nothing, and you eventually give up and spend five minutes watching the end fight that people have hyped as "way better than previous boss battles" and find out it looks entirely like a quick time event where you mash a button and it's literally called "the cure for insomnia".
And at that point, yes, you can fairly go "nope, not for me."
It'd be one thing if a game stayed secret and you didn't know it existed until a week before it came out, and then you binged everything there is to know about it… but when it's part of a 10 year long development cycle that has been extremely public? It's different.
Final Fantasy as a franchise, and Square as a company, have been going in the wrong direction for a long time. They've lost trust, and they have to show off and prove to us they've got something good to offer... besides just graphics.
Abzu back in August I got sight unseen because it was from the Flower and Journey people, I didn't even need a review. Dragon Age 3 I bought gladly without having to look too closely, because the company still had my trust. (Though their next outing I may hesitate more on since they burned me a bit just because I was on the previous generation system.)
I know almost nothing about Horizon Zero Dawn releasing in February. Or Last Guardian. But I know from the couple minutes of footage I've seen that I'm totally there. Assuming the reviews are good at all, I'll be getting it without looking any further.