Atlus hate the EU. They really, really hate it. Pretty much one of the worst companies out there.
I think that's less "hate" and more "don't have any operations there." Someone has to buy it from them to publish it there (which is usually Ghostlight these days if I understand correctly.)
That's like saying Falcom hates the rest of the world because they don't have any offices outside of Japan.
Nintendo, Capcom, and several other big names don't have that excuse.
Persona 4 arena. Region locked to avoid reverse importing from NA to Japan. Yet they also locked Europe. The consoles are quite capable of specific locking, it doesn't have to be all or nothing. They could have quite easily locked Japan from playing the NA and locked NA from playing Japanese release, while allowing Europe to buy either.
They also specifically avoided why Europe was locked out. Every time the question was asked, why is it locked?, it was always to avoid reverse importing from NA to Japan. No answer for why Europe was locked out as well, I guess "we hate Europe" is not good public relations. Not that they have any here anyway.
Other titles, they lock the 360 version. Again, they could leave it region free for Europe, yet choose to lock, even though they don't have a publisher.
Persona 4 arena, huge delays because they couldn't be bothered to give Zen United the EU build in a timely fashion. So publishers bought the game and they just sit there, with the attitude, meh, Europe.
NIS America, don't have an EU branch, yet they publish here.
All the years they have existed Atlus have made no progress at all on publishing games here in a timely fashion. They are stuck in past. Everyone else has progressed from the 6-8 months of delays EU used to suffer. Sure there is the odd game from other publishers that takes a while to get here, but for the most part, it's fine. Atlus, same old, no progress in years, still months and months of delays on their titles.
Can only hope more developers see the light and give their games to capable companies, like what happened with Dark Souls, Namco got it, not them. So it actually saw a release in a timely manner.