Yeah, even the most basic diplomacy (even during a war where it becomes apparent that you've got one friend and five enemies!!) increases xenophilia drastically. I'm actually a fanatic materialist, with only the technologist faction even existing even after 42 years; I've got droids by now (thanks to the mechanist civic for that) and my entire planetary mineral production is done by such droids. One would think that this is going to make materialist a popular choice.While I'm not in any hurry to enforce racial purity, the absolutely ridiculous level of xenophile attraction I've been getting in Banks, while not actually being a xenophile empire, is making me modestly irritated. I mean, I'm officially Egalitarian/Materialist/Pacifist, I have been at peace for a long, long, long time, I have One Vision as an ascension perk, and xenophilia attraction is easily overwhelming my pacifist attraction.
Hey guys, let's focus on making ludicrous amounts of money and how awesome our living standards are, rather than clamoring for more alien species in our republic and asking me to have diplomatic ties with all my neighbors, like the psychotic slavers directly on our borders. Ugh. I mean, it's not like I have bad policies for aliens, I literally set them all to the same rights as my own Daera, I just would prefer their focus be less 'aliens are awesome!' and more 'peace and prosperity'.
Well, it did before I got an alien friend that almost instantly joined a defensive pact and offered me free migration. Back then I would have 80% attraction towards materialism! But after not quite 20 years of good relations and a defensive pact, ALTHOUGH I'm at war for 7 years against two other empires, I'm at 50% materialism and 30% xenophilia attraction (my people start to love our enemies who could crush us instantly if they had a sense of strategy, basically). Back in the old days, most people were part of the technologist faction. Now they aren't even the majority anymore.
And I blame the "free xenos" modifier. One single pop in a 3000 main species pops empire would already be enough to make everybody a xenophile.
(and yes, I am using the +25% gov ethics attraction edict!)