I think a lot of people take good logical things that make sense in specific contexts and then over simplify them to the point they become bad advice.
Let me elaborate on a few
“Don’t study grammar”. This one is rooted in comparison of traditional school learning, which tends to heavily emphasize grammar to the point that you end up with people who can barely talk about anything beyond the weather or introducing themselves, but can do so with perfect grammar. In contrast, someone who jumped straight into speaking will likely grow a high vocabulary, and have poor grammar, and yet be able to hold more interesting conversations. Some people see that and over-correct and think “grammar is useless”.
But reality is of course more nuanced. The more truthful advice would be to not over study grammar to the point that you’re neglecting everything else. However how much will vary based on where you are in your learning journey. For me, on a perfect day, I study grammar for about 15 mins a day. I study kanji on WK probably for about 15-20 mins a day. I listen to videos for about 30 minutes, and I read my novels for about an hour. Someone else will have different numbers and that’s probably ok. But if someone is spending 5 hours a day studying grammar and less than 10 minutes putting it into practice, that’s probably not good.
So if I were to give the advice it would be “Finish your textbook (or equivalent grammar course) a little bit at a time every day, and do other stuff too”
“You must use Anki”
I don’t (at least not for the purpose most people use it for). I do use SRS in WK and NativShark, but overall that’s about 30 mins of my day. At one point I used Anki or iKnow to randomly learn stuff and at first it led to great gains, but then I started to forget more because I wasn’t giving myself time to go learn them in the wild.
So really it’s more “Use an SRS if you want, it can be very effective, but keep in mind that only relying on SRS is not a magic wand, you still have to practice”
”You must read from day one”
I’ll give you one higher. I’ve seen people say you must read ONLY native non-kid materials from day 1. Many of these people did not do so. They started out on a more traditional path, learned a little but as fast as they were hoping for, eventually got native materials and found that their skills skyrocketed. Then they think the only way to learn is to do that from day 1, ignoring that they still build a foundation with their initial methods, and ignoring that the act of reading is a form of testing and practicing what you’ve learned to help the brain glue that knowledge. However for most people starting out, this would be a frustrating experience from day 1.
On the other hand, some people get complacent and only read easy things (like N5 level graded readers) for years out of fear of ambiguity. Because of this they never get to challenge themselves.
Once again, the truth lies in the middle. You should aim for whatever is the highest level you are mostly (but not completely) comfortable reading. This level will vary per person. And that means for some people they can’t get to even a starting point until after a month or more of studying, and maybe they’re just reading premade exercises. And that can be ok as long as they don’t get stuck there.
Overall
So yeah, when I hear advice, I ask myself “what experience would have led that person to believe that” and instead of blindly following it, I try to figure out where its nuance lies. Are there specific contexts when it is somewhat valid and some where it isn’t?
And I’m not saying I’m completely right either! I hope someone is reading this and thinking about some factors I missed out on and building on their adaptation of that advice!