I have had my share of disappointments and letdowns,whether it be academically or athletically, just like everyone else. It is called life. I'm sorry, but don't use anyone else as an excuse to not tryout for the group. It's called competition. Don't you think I was nervous, doubtful, unsure, etc. when I auditioned.
Nothing is for sure in life.
I encourage you to audition because it is a worthy experience, and I hope you realize that if you don't go out and take chances in life, you will only be left with unresolved issues. If you are referring to people who have made the group in the past couple of years, than my response would be that I have seen them. I have also seen the audience on their feet applauding after every show, so we must be doing something right. Your other comments are valid, but try to avoid the slander. It only reflects poorly upon yourself.