PRESCRIPTIVISTS not welcome???

I was stunned when an influential veteran member seemed to read a junior member out of the club for being too prescriptive. I have found that many language learners (especially at the lower levels) BEG for "rules." I am currently studying Chinese and Spanish on my own, and I WANT clear and definite rules in order to boost my self-confidence. Would the following answer be acceptable to both prescriptivists and descriptivists at this website? Dear John Doe: Thank you for your question. According to traditional rules, you should say, "It is I"; however, almost all native speakers no longer follow this rule. They say, "It is me." Nevertheless, if you do any university-level writing in the future, you should be aware of this rule, even if you and your professors decide not to follow it. As a famous (infamous?) man in Los Angeles once asked: Can't we all just get along?