Why is it so common to join extremes without watching a guide first?

[Midareyukki]

People are impatient and I also think that people find watching guides akin to studying for an exam or test. You might need to do it but it's boring and a lot of people don't want to do it.

Then you fail the exam, so stop whining when the kids who did study got a better grade than you and don't want you around their group sessions to distract them.

[NekoMataMata]

Then you fail the exam, so stop whining when the kids who did study got a better grade than you and don't want you around their group sessions to distract them.

Not sure why you're so aggressive. OP asked a question and I gave an answer. I didn't support said answer nor did I complain about said answer.

[Midareyukki]

Not sure why you're so aggressive. OP asked a question and I gave an answer. I didn't support said answer nor did I complain about said answer.

How's that aggressive? xD

Anyway, the reason I say that is because I was being accused of being impatient not long before you said that. Basically you used the same words they did, so the cap fit.

Essentially, at least for me and people who think like I do, it's not really about being impatient at all. It depends on the content and on the context. If it's a Trial or a Raid, you won't have the same type of ease as a dungeon boss (unless it's designed to be a cakewalk). And if it's a Normal Raid vs a Savage Raid, there are differences on how you approach them. Normal Raids imply that you can go in and do whatever, mistakes happen and it's disorganized enough, yet people clear with minimal difficulty. Savage raids require a bit more organization and coordination, so you'll approach it with a mindset fit for that. If you choose to go in blindly on Normal Raids, odds are people will explain to you what's going on. But you'll use PF for Savage most likely, and normally people don't want you to go in blind unless they specifically specify it's okay.

And your analogy with tests or exams really doesn't work. Because it does sound like you're saying "People might want to study for an exam, but studying is boring and they don't want to do it". Which is... really weird? In an exam, usually you only have one try (two if your school's nice to you). On a fight, people tend to wipe, and if they're not the sort of jerks that leave on the first wipe, they'll stay and be understandable.
If you don't study for a test, odds are you'll fail.
If you don't watch a guide for a FF14 fight, odds are there are mechanics you'll know, stuff you won't, and people will be happy to explain.
The only time they won't be happy to explain things to you is if you join a group that specifically doesn't want to go blind. This on PF. On DF, there's common sense; you can't expect people to be good on dungeons or trials they've never done, but if they're consistently wiping to the same thing, it's kind of a sign that you need to swallow your pride and listen :x
You not studying for a test will raise the odds of you failing. And I assume this is the same in every school, but you're not allowed to ask people what to do during the exam .
You not studying any guide for a savage fight means that other people will now have to deal with you either figuring yourself out or have people explain stuff to you.

It's the same as my example with the party that refused to listen in SoS. They chose not to listen to me at all, and thus wiped a fourth time. I can't hand them the win on a silver platter. And that information was there.
It won't be there during an exam. So you choosing not to study screws you over and you alone, not seven other people.