I don't ever try to justify anything to myself. I know what's what and I can't trick myself into thinking a different way. Whenever I beat a casino as an AP, I don't try to justify it by saying they are evil and deserve it or whatever. I want to make some money and that's that.
Someone might want to make up a bunch of bullshit to justify and convince others what they are doing/did is okay, therefore, they are not unethical, I guess. As long as Im not hurting an individual personally, and I'm not going to jail for doing it, I'm good with it. example: If I bought something at WalMart and I broke it on the way home I would not have any problem taking it back and saying it was like that when I bought it. does that activity hurt everyone in the long run and push up prices? Probably. I could try to justify it by saying everyone else is doing it and I pay for that I do it myself. I won't do that because the truth is... I just don't care.
If you believe in the traditional God, just stepping foot into a casino is unethical.