Hardly. "Enemy" is a matter of perspective, but there are actual "bad guys", regardless of what side I'm on.
As a simple illustration, if you were a holocaust victim at Auschwitz, the Nazi regime is your enemy, even if you're passive in your resistance, as many were. The Nazis are also the bad guys. Even though you are the Nazis' enemy, you are not the bad guy. The bad guys are the ones murdering millions.
Often in conflicts, both sides are bad guys (for example, warring criminal gangs). The term "bad guys" doesn't necessarily mean there are "good guys" opposing them.
Thanks for your thoughtful replies. Notice though, that you've both affirmed that the Nazis did in fact do (really) bad things. You've also affirmed that the bad things they did comported with their general ideology. It was not the case that they were characteristically decent folks with a few bad apples in the bunch. It is for these reasons that I described them as "bad guys".
I think you've both missed a subtle distinction, however, and that is that there are bad things regardless of what I think about them. For example, if I were a rapist (I'm not), and if I thought rape was wonderful (I don't), what would you say to someone who said, "well he likes rape and that's just his perspective"? My guess is you would (correctly) say something akin to "yes, that is his perspective. But his perspective is wrong. Rape is wrong, he's wrong for doing it, he's wrong for liking it, and his belief that it's fine is incorrect, like believing in a flat earth." And like a belief in a flat earth, simply believing the wrong thing doesn't tell us that there is no correct view. It only tells us the person is wrong in the view he holds.
If there is no real standard of right and wrong as a distinct, discoverable feature of reality, we can never be opposed to anything on moral grounds. The most we could ever say about slavery, racism, rape, the holocaust, and anything else we know to be bad is "I don't like it, but that's just my perspective". Taken to its logical conclusion, this only leaves us with a might-makes-right world but not a moral one.
artursapek, I completely agree that "bad guys" is a term that is often used carelessly. Maybe this is even a good reason to avoid it conversationally. But when discussed in a thoughtful, precise manner I do think it stands on its own merit.
Why are criminal gangs assumed to be the bad guys here? Do you know the varied history of different gangs in the US? You might be surprised at what you find.
As DannoHung said, a lot of the nazis genuinely believed they were the good guys. Obviously what they did was horrible, but the point is that you have to assess the actions of a group like that keeping in mind that it's just composed of a bunch of individual people. And people can be persuadable, stupid, and not very far along in their ethical development (especially the very young people who are enlisted to fight).
When you consider how malleable the human mind is it's hard to take terms like "good guys" and "bad guys" seriously. Everyone grows up in their own environment, with their own perspective and traumatizing experiences. There are many people around the world who see the US as the bad guys, even though I think our intentions are noble and we obviously don't go around systematically murdering millions of people as efficiently as possible because of what they look like.
If you just mean "bad guys" to describe a group of people doing unethical things, then I agree with you but I disagree with the phrase. It just makes me think of little boys playing cowboys and indians. It's not a very thoughtful phrase.
As a simple illustration, if you were a holocaust victim at Auschwitz, the Nazi regime is your enemy, even if you're passive in your resistance, as many were. The Nazis are also the bad guys. Even though you are the Nazis' enemy, you are not the bad guy. The bad guys are the ones murdering millions.
Often in conflicts, both sides are bad guys (for example, warring criminal gangs). The term "bad guys" doesn't necessarily mean there are "good guys" opposing them.