@lanthanum, I'm quite sure not all primary school teachers know that a square is a rectangle, FWIW.
Maybe I'm not explaining myself very well (it started out as an off-the-cuff comment about the early years curriculum).
I've no issue with children picking up words for shapes. Fine. We all did it.
What I have an issue with is that children aren't just casually learning labels whose precise meaning may be slightly different from what they assumed. That's a normal part of language learning and it's fine.
My issue is that, currently, I see children being explicitly taught to memorise something that is incorrect. Not incomplete, or a bit simplified, but incorrect.
I don't like that.
In the same way, the maths lecturer in the article wasn't objecting to teachers not raising the issue of decimals or fractions when teaching counting or basic arithmetic. He was objecting to teachers telling children that there are no numbers between 0 and 1. That is a very different thing.
If a child asks you, with interest, 'mummy, what comes between 0 and 1?' it's a good question. Replying 'there are no numbers between 0 and 1' is wrong. But, unless he's making something up in that article (and I bet he isn't), that's what he's seeing happen.