Before I start ranting about other ranters, let me inform you that I go to a school where the majority of the student body is involved in Greek life. Now for some, they may think this is a problem. They may argue that "they feel left out" or "excluded" blah blah blah. I'll let you in on a little secret...no one actually cares.
Being a geed my entire college career thus far had me a little nervous at first, until I figured out it's not that deep bro. People don't exclude you because you're not in a house. Greeks don't make a big deal out of your personal choices. Now maybe this is just at my school, because of size or the close community. Whatever it is, it works.
Many times people point out (and get offended) when other students at fraternity parties often ask, "What house are in?". This happens all the time, however, you're at a fraternity party. It isn't completely random for them to ask. (And newsflash, I've answered this question hundreds of times with "I'm not in a house" and somehow I still have Greek friends). They just follow it with "Oh, that's cool so what are you studying?". It's only a big deal if you make it a big deal.
Before I knew how little of importance ones' status is on campus, my spring break plans had me worried. I was planning to go to Florida with 24 other people, all Greeks. After the first get together we had as a group, I didn't feel out of place at all. There were such a modge podge of houses and people going, that everyone knew you for going undefeated in pong, not that you were in a certain house. Now when everyone started taking house pictures, all you can do is throw up the sign of Independents everywhere *flips off camera*.
The point is, I don't think anyone has the right to say Greek life makes them feel excluded. They have every right to join if they want, and if not, more power to them. I've had a great experience at school as a GDI, and it can only go up from here. If you're set on feeling left out, you will find a way to. But if you want to live life to the fullest during your college career, just remember, no one cares unless you do.