It violates seniority. A pilot should not have to commute out of base on the hopes they might get a base trade back in. The current system should only allow a base trade if both pilots have the seniority to hold the base.

An exacerbated example is ORD 320 CAP where a guy gets in well out of seniority on a base trade, and then there is a 777 FO displacement and a bunch of guys pile in on top of him, overfilling the category, and making it so existing pilots who have seniority can't get into that category for (probably) at least a year more.

Its not about hating the people that are there, its about those pilots that have seniority and can't get what their seniority should allow them.