Also, for some people, errors like this (even those that don't cause an actual misunderstanding) jump out and distract you from whatever the meaning was.
IIFF uu dis
thihn tiry 2 reed ThIsEnTinsnadTILLME;; that, it, ,,
izCLERUR. !&$^? than whit u rot??????!!!!???!???!
Of course, there are some rules that make no sense or are completely arbitrary. There are also some "rules" that are more misunderstandings about grammar than actual grammatical concerns. For example, "Don't end a sentence with a preposition" is often repeated, but is not actually a part of the grammar of English. So it is entirely possible for someone to judge someone else based on an incorrect understanding of what writing correctly actually is.