Miami is definitely the most culturally diverse city I have ever lived in, but somehow, people still manage to judge. During my first year here, the kids used to make fun of me for having a British accent because of my studies in a British school in Madrid. I even got made fun of for my Spanish accent when I spoke Spanish because of the lisp the Spanish have when they speak (compared to many of the local Cubans). In the other countries, I was judged for the people I spent my time with. But in the United States, I was the source, and it felt different.
Some applicants may ramble on about themselves in a manner that may appear self-indulgent and not very appealing to the committee. Remember, this is an application essay, not an autobiography. Conversely, some applicants tend to say too little, perhaps hesitating to promote themselves too explicitly or not knowing what about themselves would be interesting to people whom they don't know. In such cases, perhaps focusing more on what you want to do than on what you have already done (let your record speak for itself) may help in getting beyond self-inhibition.