How exactly does sophmore "disadvantage" hapen?

[NYCbelle]

Hi!
I am new to these boards but have a few questions about how rush works. When I rushed things didn't work out well - I rushed as a sophmore and attended prefs at my two favorite houses - would've been super psyched to join either one. But I didn't get a bid to either which made me really sad of course. I assume I was at the end of both bid lists (the house I put second claims they got their whole first list so that's why I am led to believe I was at the end of both).

To be honest I can believe I was in the bottom half of the list for both houses - I'm chatty, good grades, attractive enough but not "oh, she's sooo cute", involved in stuff but not any bigtime campus leader, etc. But people told me it was because I was a sophmore (not people in the houses per se but others). I'm not so sure. Now I understand why a sorority would not want a bunch of sophmores especially at a school that has a ton of wonderful freshman available (mine did - in fact they brough in 3 new sororities the next year and just about every house was over ceiling still, even 1 of the new ones). So how does this sophomore issue actually work - is it a) that members automatically think a bit less of you b/c they wonder why you didn't pledge last year or b) they are reminded/cautioned when it is time to vote that you are a sophmore so they should be more strict on your vote/rank or c) the bid lists are actually adjusted before they are turned in to make sure not too many sophomores are in the top of the list. I know this is so nit-picky but I really want to know b/c I am still hurting over the whole thing! When I read stuff about schools where a girl is guaranteed one of her pref houses it makes me want to cry b/c I would've been so happy at either one!!
Thanks!