According to people I know who are teachers, schools no longer stress grammar and spelling. The kids are “going to do it wrong, anyway,” so the teachers have thrown in the towel. I guess prior generations were capable of learning spelling and grammar, but today’s kids cannot or will not.
Another problem is that often, the teachers themselves are rotten at spelling and grammar.
Besides, using proper grammar is a “White Thing,” it ain’t keepin’ it real, y’know what I’m saying?