Why do I get houses I asked to drop?

PNMs aren't actually able to drop houses during formal recruitment. If you got back houses you ranked 2, 3, etc. it's because at least one of the houses you ranked as a 1 did not have room to invite you back. After sororities make their list of who to invite back to their house, it depends on where you end up on the list compared to other PNMs that determine what houses you are invited back to. Let's say that PNM A ends up being listed first on every sorority's list of invites back for the next round-- that's when the PNM rankings come into play and the PNM would only go back to houses they had ranked as a 1.

Here's another way of looking at it: There are three sororities, Sorority 1, Sorority 2, and Sorority 3. Each house can invite back 10 PNMs, but each PNM can only go back to 2 houses. If every sorority's PNM list is A, B, C, D, E, F, G, etc., and every PNM ranks the sororities as 1, 2, 3, then PNMs A-J will receive invites back to Sorority 1 and 2. But PNM K will receive an invite back to Sorority 3, even though the PNM ranked that house last and the house ranked the PNM lower. PNMs move down their house preferences as the spots at each sorority are taken up, and houses move down their PNM list as the PNM schedules fill up. This isn't always the case, but probably explains what you're asking about.

On a side note as a bit of a warning, even if you get an invite back to a house you're sure you don't have a connection with, still try to go into the party with an open mind or at least with a polite demeanor. Recruitment chairs/presidents of the sororities talk, and if a PNM displays really rude behavior at a house they don't like, that could very easily get back around to the houses you do like and mess up your chances there. It's okay to know a place isn't for you, but it's not okay to be rude or mean. Panhellenic love is a thing (even if it's not as obvious during formal recruitment lol). If you do end up in another house, you'll still attend events or even just have classes with other women across the row.

I would say it’s unfair to judge a house based off of one 30 minute visit where you’re interacting with three out of likely 200ish members. Keep an open mind and welcome the opportunity to give a house a second chance