Explaining is not absolving nor justifying. Someone who explains why he murdered is still a murderer and no less of a murderer. That you (hypothetically speaking) were a victim of child abuse does not make it okay for you to abuse your own child in return. It just means it's more likely that you will. I'm trying to explain why the Roma are the way they are. which was the original question I was answering. I don't excuse their behavior. You have to understand the problem before you can truly fix it, otherwise you make blunders that make things worse instead of better.

these events were just inflicted upon them in thin air, with no cause or reason.

That is twisting my words. I never said that. I've said several times now both sides have good reason to distrust the other. Neither side is innocent.

We're (generally) more enlightened

Are we? I don't know about that one. Sarajevo and Bosnia wasn't so long ago. Nor was Rwanda. And the US is sliding backwards and hatred and fascism is on the rise both in the US and in Europe. Authoritarianism growing, poverty and social unrest rising. Europe's dealing with a migrant crisis and it wouldn't surprise me to see Roma get caught in it. Calais shut down just last fall, in flames. Promises not kept.

The Roma aren't innocent. I don't want the European Roma anywhere near me either. I just think trying to take a hardline punitive attitude towards them will backfire badly.

We both agree they're a big problem (though maybe the migrants are a bigger one, being far bigger in numbers). I'm not okay with the filth, theft, and overall criminality either. I think where we disagree is what to do about it. We have different beliefs about what will and won't work. It seems unlikely either of us will ever persuade the other.