My wife is in a California English Language Teaching certification course online with the University of Phoenix - they have a similar online writing based curriculum. From time to time, she lets me read some of the things her classmates are writing. From what I have seen, a substantial number of educators in the state of California often have terrible writing skills. Their spelling is not great, either. There are many schools in San Diego where school children receive little or no help at home with reading or writing, not to mention math, science, art, or history. Teachers are really the first and only line of defense between these kids and illiteracy. Since most students don't do much reading or writing on their own outside of facebook posts or texting, it is unlikely that they will learn writing skills by experiencing good writing. If their teachers haven't got it together, there is very little chance that anyone else is going to set them aright.
Naturally, these kids grow up and start applying to colleges. Some of them are accepted and must be responsible for the awful blog posts you're talking about.