The two really can't be compared. Housing is a basic need whereas a sorority is definitely not. The equivalent of "Nobody drops just because of the money" would be that "Nobody is homeless just because of the money," which is true. Nobody sits around and says, "OK, well, I used to have money but now I don't so I think I'll become homeless." Whenever somebody is homeless, there are deeper issues at play -- usually that they lack the skills to be able to pull themselves up. That is the bigger problem. The lack of money is, again, not the basic issue.
Not to mention that college students cannot be compared to homeless people because we have the inherent advantage of having at least a high school education or equivalent and marketable skills if not a degree, and they don't always have all or any of those.
The thing is, with sorority dues there is ALWAYS a way to pay. People overestimate how expensive they are. You don't have to be wealthy to manage it. Even the most expensive dues at my school could be covered by a 10-hour-a-week student gofer job. My own dues could be covered by a couple of plasma donations each week. Most college students could save a couple hundred bucks each semester if not more just by making lifestyle changes -- not ordering that late night pizza once a week, buying their textbooks used, not drinking so much

. There is always, always a way to pay. Is that way always easy? Definitely not. I have friends who have worked a full-time job and a second part-time job in addition to going to school full-time just to be able to cover their expenses. Would I be able to do that under normal circumstances? No. Would I do it if I had to? Of course. And would I do it if I wanted something enough, and that something was expensive? Definitely.
But if a member decides that she can't pay $1000 a semester for an experience, she's saying, basically, that that experience is not WORTH $1000 a semester. That doesn't make her a bad person. It doesn't even make her sorority a bad sorority. But it does mean that she feels she was charged too much for what she got out of it.