I wouldn't worry about it too much.
Regardless of your ability you're going to run into both groups of people. I haven't done any of the 50 dungeons yet and I'm not worried about it. The good thing about the people who consider themselves elitists is that other people will begin to learn who they are and avoid them and they will eventually only run with certain people. Which is fine by me. I'll take my time, learn the dungeons and teach others I group with who doesn't know them, and when my FC mates gets to end game we'll all run with each other and at least enjoy each others company.

First time I did Garuda in this game, my first party we wiped over and over for the full 90 minutes. the second party we wiped for 45 minutes until people quit. My 3rd group I took the time to explain everything Garuda did in detail and every move ahead of time and it took us 3 attempts and I was the only who had fought her before.