Anyone who makes a grammatical error is immediately wrong, no matter how grounded in facts their argument may be. Think about it: if you don't remember every single bit of minutiae you learned in eighth grade English class, how can you be taken seriously? Grammar is an essential component to getting any job in the modern economy. Librarians, English teachers, and spinster book club members are the most respected members of society; is it any coincidence that they comprise the majority of our nation's self-appointed grammar police? The bottom line is if you can't keep your "yours" and "theres" straight, you certainly aren't capable of holding an opinion or stating a fact.