For example, my father (ENTJ) has gone into business with an ENFP from Ireland. He said to me over the phone that this ENFP was writing what they wanted on the website. I exclaimed at him releasing control to an ENFP of all people, in jest. His remark came back "Oh no he's quite good. I rarely have to correct much." now with MBTI knowledge I know he didn't mean it to sound patronising... not that I let him off with it
My SO is an ESTP and she's a messy person. Now without having studied other ways of thinking, through MBTI, I would constantly chastise her over the mess. She'd get peeved and no doubt I'd have left. With that knowledge I can berrate her much more effectively
Perhaps your message should be "Be careful how you weild that system" more so than "MBTI sucks"?
I must say though, from an MBTI perspective, you don't sound like an ESFP. I'm not saying you aren't, I'm just a little surprised (that's a good thing btw).