Students in fields where their endeavors are formally and logically reviewed rely on skillets which differ than those of most people. For instance, the language skill sets which are needed to impress in Performance Art in the Theater Arts Department (e.g. what color am I feeling today) is substantially different from the ones needed in epistemology.
To most people persuasive skills are far more important than logical ones. Most any occupation I can think of: lawyers, priests, reporters, politicians, businessmen, policemen, prison guards, pimps, drug sellers, authors, musicians, and actors all usually have a greater emphasis on persuasive arguments over logic ones.
At this point I would expect most reading this to wonder what any of the above has to do with language and grammar skills. I concede that clearly those skills are of value to those in the fields listed above. My point, if you’ll bear with me a bit longer, is perhaps a bit more subtle. From the perspective of the average person living in the US, persuasive activities do not require to nearly the same extent the rigid formality required by logical activities. Unless required by work or school there is little societal requirement for grammar. Of the tools people feel they need to succeed in life grammar is viewed by most as the tool of lesser value than the tool of persuasion.