Ok I may be a little bias but I truly believe that CrossFit is for everyone. Not only can everyone participate, but CrossFit can develop you into a stronger version of yourself.
Your Only As Strong As Your Weakest Link
One of the reasons that CrossFit is so effective at creating athletes is its ability to uncover weaknesses. Many people end up resting on their athletic laurels and this puts them at risk.
For instance in high school I was the skinny kid that ran cross country. I used to run 20 miles a week in short shorts. I thought I was in fantastic shape. But if something happened where I had to display the smallest amount of strength I was doomed. God forbid if I had to carry in the 40 pound bag of dog food into the house.
This is the usual for most "athletic" people. They will find one form of fitness that they really like, whether it be yoga, mountain biking, or even body building and will let all other physical activities go. Even though you may currently be flexible, or fit, or strong, you will never be all three while training like that.
CrossFit exposes these weak points and makes you develop each one of them. By doing this we can become more well rounded physically and can take on many more adventures than someone that focuses solely on one facet of fitness.
We Are Stronger United
Did you know that people are consistently more afraid of public speaking than they are of death? This fear is derived from a primal instinct that we must become part of a tribe lest we be outcasted and starve.
That same fear is the one that drives us to work so hard during CrossFit workouts. Since our classmates are our friends and neighbors we fear letting them down, which makes us push through those final reps when we want to quit. It just so happens that this is where we grow the most; when we are outside our comfort zone.
This is quite a positive and powerful experience when you have a whole class cheering for you as you finish your workout.
Anyone Can Do It
Many people believe that some people just "have it" and other people don't. Every time I tell someone that I own a CrossFit gym the response is always the same: "Oh, I could never do that. I'm not that strong."
This is not true. No matter who you are you always start at the bottom. Your first three months of CrossFit are a fun time of rapid growth and learning. You will make more progress physically then, than any other time in your life.
You do not need to be in the best shape of your life to start. But to be in the best shape of your life, you do need to start.