Grammar is definitely taught at schools, it's just done in a completely different way to how us older generation (30+) are used to expecting it. Certainly at KS1&2 anyway, which in fairness is when the basics are set. The bigger issue is lack of stability in the curriculum to enable cohesive teaching: Every time we get a new government in we get a new SoE, and then everything changes again. Even worse when we get an entirely different party and the whole ethos flips around.
What it needs is cross-party support for a 10-20 year curriculum that doesn't get altered. It gives the kids stability so they get used to learning a certain way, it gives teachers stability so they can concentrate on teaching not figuring out how to please Ofsted, and it gives parents stability so they can see that all their children are learning the same way and can track progress. Sadly, there's too much point scoring out there right now to make that a viable idea.