Avram, notasheep: I have no problem with someone asking to switch seats. I don’t sneer at anyone for it. Avram, you mentioned asking to deplane. If a chareidi wants to get off the plane because (s)he will have to sit next to the opposite gender, that’s fine. My issue is when planes are delayed because either they wait until the last second to decide to leave, or when they refuse to sit down, but want to stay on the plane. Either case causes other people to look at them in a bad light, and causes a chillul Hashem.
You want to leave the plane if you can’t get a seat you find acceptable? Fine, but get there early enough so you don’t cause a delay. I have absolutely no problem with that.
As for spending extra money for a seat (as DaasYochid posted about): so it costs a lot. So what? How much is halachah worth? We spend thousands of dollars extra every year to ensure we eat only glatt kosher meat, many people spend extra to eat/drink only chalav Yisrael. For Pesach, how much is spent on cleaning help to ensure that we go beyond the requirements of cleaning for Pesach? How much do we spend on the extra-mehudar hand made matzos when machine shmurah matzah can be just as acceptable? The fact is that we spend tens of thousands of dollars every year on things that are really chumros, but are important to us. Why should this be any different?