I think few people would say it's a "lesser evil" but something that is morally fine and should be legal (when no money is changing hands).
If you were, say, selling abandonware that's much more of a murky area, but just downloading a copy or giving people a copy of some data that is no longer sold - whoever has ended up with the copyright shouldn't be able to complain if they are not actually making it available for purchase - they shouldn't be able to claim any loss since by not selling it they are not being deprived of any revenue.
Of course, part of this is only a problem because copyright terms became absurdly long - if we had sane copyright terms like strictly 25 or 30 years from publication a lot of this stuff would be public domain by now anyway.
I don't disagree that it's morally fine -- after all, the abandonware community wouldn't make the downloads available otherwise -- but it's still not legal.
Home of the Underdogs used to get tons of aggressive cease and desist emails from ESA (then named IDSA), the group representing game publishers legally, and who supposedly are on the "side" of games. So aggressive in fact they sometimes got it wrong (like sending a C&D for a game which was public domain). And who was willing to take a stance and chance it?
Back then the abandonware community was one of two things, I think: people who just wanted to download games (Warez or abandonware was the same to them) and proper members of the community, who'd rather see these games either commercially supported or made public domain. Both HOTU and Abandonia replaced download links whenever someone found a legal way to buy the games.
If you were, say, selling abandonware that's much more of a murky area, but just downloading a copy or giving people a copy of some data that is no longer sold - whoever has ended up with the copyright shouldn't be able to complain if they are not actually making it available for purchase - they shouldn't be able to claim any loss since by not selling it they are not being deprived of any revenue.
Of course, part of this is only a problem because copyright terms became absurdly long - if we had sane copyright terms like strictly 25 or 30 years from publication a lot of this stuff would be public domain by now anyway.