You'd just have to deal with it if you want a full party. There's nothing mechanically different except the strength of the enemies you have to fight. I think it was you that made the thread about people bringing friends to PL unannounced which is the only bad thing about it IMO. Lay down ground rules and go with what's available instead of always wanting to be a full party just because you can.

People have aversions to "spam fest" parties and smaller parties feel more tactical and fun to me.