Have you wondered why we all spell things the same way, well not quite, as in England we spell things differently from the States - same with Spanish from Spain and Spanish from South America, but generally it's pretty uniform.
Also, did you know that the structuring of sentences (e.g. some people beLIEve that a sentence MUST have a subject, verb, and no more than one adjective... must all be in the same tense... and same "person")... is a very recent invention?
It blocks the free flow of information and energy behind the words. Not only of writing it, but also of it being received. If the writing has "mistakes" or "errors", a person stuck in the "grammar matrix" will not be able to understand it, or will get terribly distracted by these "errors in grammar" and miss the point, thought, or energy being carried in the piece they were reading. It creates minds that are barren (only in expression), restricted and overall unsure of how to express fully, without mistakes.