'Why isn't grammar taught well, if at all, any more? Why the assumption that children will find it dull and difficult?'
Oooh. Don't even get me started on that one!
My understanding is that the CLC was a laudable attempt to overcome the fact that learning Latin meant a lot of (arguably - not if you're actually interested in how language works) dry grammatical stuff; whereas in French or other modern languages, the teaching approach has always been much more conversational/situation based. The thinking was that this is more fun & more approachable.
BUT Latin is an inflected language, ie. different grammatical meanings are conveyed by different word endings, whereas modern European languages use the position of words in a sentence.
If you learn Latin properly, it lays bare how language fits together. If you rush into learning enough vocab. to read continuous prose, without getting your head around why the word endings continually change, you are going to end up hopelessly confused - with the notion that Latin is 'difficult' firmly reinforced.
Also, the CLC is dull dull dull. Not much point rushing students into 'reading' (sort of) continual prose, if it turns out that after slogging through a page of it, the most exciting thing to happen is Hermogenes being bang to rights on his debts because he's neglected to remove the ring with the seal he used to sign the contract...
Honestly, that's as thrilling as it gets.
In fact ignore what I said earlier about checking it out online, yurtgirl - I suggested that as it's widely used & there are lots of online resources - but other posters have offered FAR better suggestions.