When I was in school, the goal was to educate students to either continue education in college or to be able to function in the labor pool. Now, schools are a day care center that incidentally attempt to teach some basics. The testing techniques are only a symptom of the problem. Parents used to encourage the completion of homework and assist in the teaching process, as they knew their kids better than the teachers could. Now the parent(s) have little time or energy to spend on their kids education. This assumes that in this day of children having children, that the parent(s) could actually understand the kids homework.
I don't see this as a sinister government plot or evil business strategy. I see it as part of the system slowly failing and beaurocrats trying to shovel shit against the tide. The charter schools are likely being used as a type of triage. They appear to be a place to stick the real problem kids in the hope that the ones who have a chance won't be dragged down with them. And who knows? They might actually learn something. That would be a twofer. At the end of the day, though, the parents still need to be involved and with todays economic and social pressures, that isn't likely to happen. The tests will continue to be dumbed down, because the politicians can't have a 60% failure rate in schools. There will be less and less respect for learning. When the system fails completely, I don't know what will happen, but I doubt it will be pretty.