Well, bear in mind they've also nerfed federations by locking them behind traditions and thus, I suspect, making them rarer. That's an indirect buff to the purger playstyle.
And my personal feeling is that purging should be rare and should necessitate a certain, very different playstyle. I play xenophobes quite a lot actually and usually turn purging policy off, it's interesting to have the option there, but I don't think it should be the default playstyle of anything except hive minds and fanatic purifiers. Regular xenophobes are generally better served by being a bit more pragmatic, and I'd expect that to continue.