From where I sit, some of the teachers are overworked and don't have enough time to grade papers/give mostly multiple choice tests so the kids do little writing/can't write or spell themselves. I'm not saying it's all the teachers' fault, by any means whatsoever. But I know the two kids who live in our house get much less feedback from their teachers than I got in a small rural school in Mississippi that had combined grades because there weren't enough classrooms. They grade each other's daily papers with about as much accuracy as you'd expect from that system. Many of the tests are downloaded from some site that the school system subscribes to, and I couldn't tell you how many times I've complained because the questions don't even make sense. You can't tell what they're asking for.
In fairness, the teachers have a lot more committee work and paper work than my teachers did, and they're working hard from the time they get there until they go home. They have heavy workloads. But a lot of things that are required of them could go by the board, as far as I'm concerned, and they could spend more time with the kids and their work.
But occasionally, the teacher just can't cut the mustard. When our older kid went to her fourth grade classroom the first day, the teacher had nicely decorated the room and had written all sorts of things on the chalk and white boards. I counted four grammatical errors and three misspelled words that first day. How the hell can the kid get it right if the teacher can't get it right? And this is a VERY highly rated school district in Houston.
And NOBODY pays any attention to spelling!
ETA: @MLT2007, that one drives me up the wall.