You are not incorrect. At least not per se incorrect when considering your specific example of a linear teacher. That being said, for your argument to have weight more generally, you'll need to now explain how it does not reduce to absurdity; because, and for your argument to be True, it necessitates as many means and modes of teaching as there are students...
I can understand this but I'm not going to make any further explanations as in order to do so I would have to think it through more thoroughly to be happy with what I write. All I can say is that it is not necessary for there to be as many means of teaching as there are students. It's all about the approach you take with the students. But most importantly the student has to pay attention and has to want to learn, which isn't always the case.
My worry is that the talented get missed in an effort to accommodate students that are not teachable. And yes -- some students are simply not teachable, for the reasons they are not, whatever those reasons may be.
Define what you mean by non teachable. In my opinion the non teachable are those who don't care, those who don't really want to learn, and those who don't even try.
The truly talented ones are usually the proactive ones, those who take the initiative to look into things in more detail, those who don't wait for others.
But then again it depends on what you mean by "talented".
The fact of the matter is that the U.S educational system was exponentially more standardized in the days of dirt schoolroom floors, penny pencils and chalkboards; and, the students learned better and at a higher caliber over the course of their educational career. Things have gone from bad to worse, and America wants to solve the problem by throwing Ipads at kids; better computers... There's something going on, mate. It's complicated, no doubt; and it is not always the teacher. I would be sold bold as to say it may rarely be the teacher.
Well, maybe that's because back in the days there was rigor and teachers wouldn't allow their students to sit on their heads. Nowadays teachers can't do shit or else they will get sacked or sued. Back in the days, if students acted like some of them do now, they'd get beaten. There are those who use violence towards teachers, both mental and physical, and guess what, nothing is done to them. You know why? Because no one gives a fuck and because of the way things work. There's so much more to this, but there's simply no point in getting into it.
And when I make my replies I'm not only looking at the US, I'm in the UK, but I'm looking at things from various perspectives. Countries in Eastern Europe are more strict with their education and achieve much better results then countries like the UK. That doesn't mean anything in particular but generally what students in the UK learn at the age of 18, most of the Eastern European ones already know at 16. Obviously there is much more to this then just that, but rigor and attitude towards learning has a lot to do with it.